(function (global, factory) {
  if (typeof define === 'function' && define.amd) {
    define('webextension-polyfill', ['module'], factory)
  } else if (typeof exports !== 'undefined') {
    factory(module)
  } else {
    const mod = {
      exports: {}
    }
    factory(mod)
    global.browser = mod.exports
  }
})(this, function (module) {
  /* webextension-polyfill - v0.5.0 - Thu Sep 26 2019 22:22:26 */
  /* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
  /* vim: set sts=2 sw=2 et tw=80: */
  /* This Source Code Form is subject to the terms of the Mozilla Public
   * License, v. 2.0. If a copy of the MPL was not distributed with this
   * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  'use strict'

  if (typeof browser === 'undefined' || Object.getPrototypeOf(browser) !== Object.prototype) {
    const CHROME_SEND_MESSAGE_CALLBACK_NO_RESPONSE_MESSAGE = 'The message port closed before a response was received.'
    const SEND_RESPONSE_DEPRECATION_WARNING = 'Returning a Promise is the preferred way to send a reply from an onMessage/onMessageExternal listener, as the sendResponse will be removed from the specs (See https://developer.mozilla.org/docs/Mozilla/Add-ons/WebExtensions/API/runtime/onMessage)'

    // Wrapping the bulk of this polyfill in a one-time-use function is a minor
    // optimization for Firefox. Since Spidermonkey does not fully parse the
    // contents of a function until the first time it's called, and since it will
    // never actually need to be called, this allows the polyfill to be included
    // in Firefox nearly for free.
    const wrapAPIs = extensionAPIs => {
      // NOTE: apiMetadata is associated to the content of the api-metadata.json file
      // at build time by replacing the following "include" with the content of the
      // JSON file.
      const apiMetadata = {
        alarms: {
          clear: {
            minArgs: 0,
            maxArgs: 1
          },
          clearAll: {
            minArgs: 0,
            maxArgs: 0
          },
          get: {
            minArgs: 0,
            maxArgs: 1
          },
          getAll: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        bookmarks: {
          create: {
            minArgs: 1,
            maxArgs: 1
          },
          get: {
            minArgs: 1,
            maxArgs: 1
          },
          getChildren: {
            minArgs: 1,
            maxArgs: 1
          },
          getRecent: {
            minArgs: 1,
            maxArgs: 1
          },
          getSubTree: {
            minArgs: 1,
            maxArgs: 1
          },
          getTree: {
            minArgs: 0,
            maxArgs: 0
          },
          move: {
            minArgs: 2,
            maxArgs: 2
          },
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          removeTree: {
            minArgs: 1,
            maxArgs: 1
          },
          search: {
            minArgs: 1,
            maxArgs: 1
          },
          update: {
            minArgs: 2,
            maxArgs: 2
          }
        },
        browserAction: {
          disable: {
            minArgs: 0,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          enable: {
            minArgs: 0,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          getBadgeBackgroundColor: {
            minArgs: 1,
            maxArgs: 1
          },
          getBadgeText: {
            minArgs: 1,
            maxArgs: 1
          },
          getPopup: {
            minArgs: 1,
            maxArgs: 1
          },
          getTitle: {
            minArgs: 1,
            maxArgs: 1
          },
          openPopup: {
            minArgs: 0,
            maxArgs: 0
          },
          setBadgeBackgroundColor: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          setBadgeText: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          setIcon: {
            minArgs: 1,
            maxArgs: 1
          },
          setPopup: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          setTitle: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          }
        },
        browsingData: {
          remove: {
            minArgs: 2,
            maxArgs: 2
          },
          removeCache: {
            minArgs: 1,
            maxArgs: 1
          },
          removeCookies: {
            minArgs: 1,
            maxArgs: 1
          },
          removeDownloads: {
            minArgs: 1,
            maxArgs: 1
          },
          removeFormData: {
            minArgs: 1,
            maxArgs: 1
          },
          removeHistory: {
            minArgs: 1,
            maxArgs: 1
          },
          removeLocalStorage: {
            minArgs: 1,
            maxArgs: 1
          },
          removePasswords: {
            minArgs: 1,
            maxArgs: 1
          },
          removePluginData: {
            minArgs: 1,
            maxArgs: 1
          },
          settings: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        commands: {
          getAll: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        contextMenus: {
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          removeAll: {
            minArgs: 0,
            maxArgs: 0
          },
          update: {
            minArgs: 2,
            maxArgs: 2
          }
        },
        cookies: {
          get: {
            minArgs: 1,
            maxArgs: 1
          },
          getAll: {
            minArgs: 1,
            maxArgs: 1
          },
          getAllCookieStores: {
            minArgs: 0,
            maxArgs: 0
          },
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          set: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        devtools: {
          inspectedWindow: {
            eval: {
              minArgs: 1,
              maxArgs: 2,
              singleCallbackArg: false
            }
          },
          panels: {
            create: {
              minArgs: 3,
              maxArgs: 3,
              singleCallbackArg: true
            }
          }
        },
        downloads: {
          cancel: {
            minArgs: 1,
            maxArgs: 1
          },
          download: {
            minArgs: 1,
            maxArgs: 1
          },
          erase: {
            minArgs: 1,
            maxArgs: 1
          },
          getFileIcon: {
            minArgs: 1,
            maxArgs: 2
          },
          open: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          pause: {
            minArgs: 1,
            maxArgs: 1
          },
          removeFile: {
            minArgs: 1,
            maxArgs: 1
          },
          resume: {
            minArgs: 1,
            maxArgs: 1
          },
          search: {
            minArgs: 1,
            maxArgs: 1
          },
          show: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          }
        },
        extension: {
          isAllowedFileSchemeAccess: {
            minArgs: 0,
            maxArgs: 0
          },
          isAllowedIncognitoAccess: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        history: {
          addUrl: {
            minArgs: 1,
            maxArgs: 1
          },
          deleteAll: {
            minArgs: 0,
            maxArgs: 0
          },
          deleteRange: {
            minArgs: 1,
            maxArgs: 1
          },
          deleteUrl: {
            minArgs: 1,
            maxArgs: 1
          },
          getVisits: {
            minArgs: 1,
            maxArgs: 1
          },
          search: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        i18n: {
          detectLanguage: {
            minArgs: 1,
            maxArgs: 1
          },
          getAcceptLanguages: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        identity: {
          launchWebAuthFlow: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        idle: {
          queryState: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        management: {
          get: {
            minArgs: 1,
            maxArgs: 1
          },
          getAll: {
            minArgs: 0,
            maxArgs: 0
          },
          getSelf: {
            minArgs: 0,
            maxArgs: 0
          },
          setEnabled: {
            minArgs: 2,
            maxArgs: 2
          },
          uninstallSelf: {
            minArgs: 0,
            maxArgs: 1
          }
        },
        notifications: {
          clear: {
            minArgs: 1,
            maxArgs: 1
          },
          create: {
            minArgs: 1,
            maxArgs: 2
          },
          getAll: {
            minArgs: 0,
            maxArgs: 0
          },
          getPermissionLevel: {
            minArgs: 0,
            maxArgs: 0
          },
          update: {
            minArgs: 2,
            maxArgs: 2
          }
        },
        pageAction: {
          getPopup: {
            minArgs: 1,
            maxArgs: 1
          },
          getTitle: {
            minArgs: 1,
            maxArgs: 1
          },
          hide: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          setIcon: {
            minArgs: 1,
            maxArgs: 1
          },
          setPopup: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          setTitle: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          },
          show: {
            minArgs: 1,
            maxArgs: 1,
            fallbackToNoCallback: true
          }
        },
        permissions: {
          contains: {
            minArgs: 1,
            maxArgs: 1
          },
          getAll: {
            minArgs: 0,
            maxArgs: 0
          },
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          request: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        runtime: {
          getBackgroundPage: {
            minArgs: 0,
            maxArgs: 0
          },
          getPlatformInfo: {
            minArgs: 0,
            maxArgs: 0
          },
          openOptionsPage: {
            minArgs: 0,
            maxArgs: 0
          },
          requestUpdateCheck: {
            minArgs: 0,
            maxArgs: 0
          },
          sendMessage: {
            minArgs: 1,
            maxArgs: 3
          },
          sendNativeMessage: {
            minArgs: 2,
            maxArgs: 2
          },
          setUninstallURL: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        sessions: {
          getDevices: {
            minArgs: 0,
            maxArgs: 1
          },
          getRecentlyClosed: {
            minArgs: 0,
            maxArgs: 1
          },
          restore: {
            minArgs: 0,
            maxArgs: 1
          }
        },
        storage: {
          local: {
            clear: {
              minArgs: 0,
              maxArgs: 0
            },
            get: {
              minArgs: 0,
              maxArgs: 1
            },
            getBytesInUse: {
              minArgs: 0,
              maxArgs: 1
            },
            remove: {
              minArgs: 1,
              maxArgs: 1
            },
            set: {
              minArgs: 1,
              maxArgs: 1
            }
          },
          managed: {
            get: {
              minArgs: 0,
              maxArgs: 1
            },
            getBytesInUse: {
              minArgs: 0,
              maxArgs: 1
            }
          },
          sync: {
            clear: {
              minArgs: 0,
              maxArgs: 0
            },
            get: {
              minArgs: 0,
              maxArgs: 1
            },
            getBytesInUse: {
              minArgs: 0,
              maxArgs: 1
            },
            remove: {
              minArgs: 1,
              maxArgs: 1
            },
            set: {
              minArgs: 1,
              maxArgs: 1
            }
          }
        },
        tabs: {
          captureVisibleTab: {
            minArgs: 0,
            maxArgs: 2
          },
          create: {
            minArgs: 1,
            maxArgs: 1
          },
          detectLanguage: {
            minArgs: 0,
            maxArgs: 1
          },
          discard: {
            minArgs: 0,
            maxArgs: 1
          },
          duplicate: {
            minArgs: 1,
            maxArgs: 1
          },
          executeScript: {
            minArgs: 1,
            maxArgs: 2
          },
          get: {
            minArgs: 1,
            maxArgs: 1
          },
          getCurrent: {
            minArgs: 0,
            maxArgs: 0
          },
          getZoom: {
            minArgs: 0,
            maxArgs: 1
          },
          getZoomSettings: {
            minArgs: 0,
            maxArgs: 1
          },
          highlight: {
            minArgs: 1,
            maxArgs: 1
          },
          insertCSS: {
            minArgs: 1,
            maxArgs: 2
          },
          move: {
            minArgs: 2,
            maxArgs: 2
          },
          query: {
            minArgs: 1,
            maxArgs: 1
          },
          reload: {
            minArgs: 0,
            maxArgs: 2
          },
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          removeCSS: {
            minArgs: 1,
            maxArgs: 2
          },
          sendMessage: {
            minArgs: 2,
            maxArgs: 3
          },
          setZoom: {
            minArgs: 1,
            maxArgs: 2
          },
          setZoomSettings: {
            minArgs: 1,
            maxArgs: 2
          },
          update: {
            minArgs: 1,
            maxArgs: 2
          }
        },
        topSites: {
          get: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        webNavigation: {
          getAllFrames: {
            minArgs: 1,
            maxArgs: 1
          },
          getFrame: {
            minArgs: 1,
            maxArgs: 1
          }
        },
        webRequest: {
          handlerBehaviorChanged: {
            minArgs: 0,
            maxArgs: 0
          }
        },
        windows: {
          create: {
            minArgs: 0,
            maxArgs: 1
          },
          get: {
            minArgs: 1,
            maxArgs: 2
          },
          getAll: {
            minArgs: 0,
            maxArgs: 1
          },
          getCurrent: {
            minArgs: 0,
            maxArgs: 1
          },
          getLastFocused: {
            minArgs: 0,
            maxArgs: 1
          },
          remove: {
            minArgs: 1,
            maxArgs: 1
          },
          update: {
            minArgs: 2,
            maxArgs: 2
          }
        }
      }

      if (Object.keys(apiMetadata).length === 0) {
        throw new Error('api-metadata.json has not been included in browser-polyfill')
      }

      /**
       * A WeakMap subclass which creates and stores a value for any key which does
       * not exist when accessed, but behaves exactly as an ordinary WeakMap
       * otherwise.
       *
       * @param {function} createItem
       *        A function which will be called in order to create the value for any
       *        key which does not exist, the first time it is accessed. The
       *        function receives, as its only argument, the key being created.
       */
      class DefaultWeakMap extends WeakMap {
        constructor (createItem, items = undefined) {
          super(items)
          this.createItem = createItem
        }

        get (key) {
          if (!this.has(key)) {
            this.set(key, this.createItem(key))
          }

          return super.get(key)
        }
      }

      /**
       * Returns true if the given object is an object with a `then` method, and can
       * therefore be assumed to behave as a Promise.
       *
       * @param {*} value The value to test.
       * @returns {boolean} True if the value is thenable.
       */
      const isThenable = value => {
        return value && typeof value === 'object' && typeof value.then === 'function'
      }

      /**
       * Creates and returns a function which, when called, will resolve or reject
       * the given promise based on how it is called:
       *
       * - If, when called, `chrome.runtime.lastError` contains a non-null object,
       *   the promise is rejected with that value.
       * - If the function is called with exactly one argument, the promise is
       *   resolved to that value.
       * - Otherwise, the promise is resolved to an array containing all of the
       *   function's arguments.
       *
       * @param {object} promise
       *        An object containing the resolution and rejection functions of a
       *        promise.
       * @param {function} promise.resolve
       *        The promise's resolution function.
       * @param {function} promise.rejection
       *        The promise's rejection function.
       * @param {object} metadata
       *        Metadata about the wrapped method which has created the callback.
       * @param {integer} metadata.maxResolvedArgs
       *        The maximum number of arguments which may be passed to the
       *        callback created by the wrapped async function.
       *
       * @returns {function}
       *        The generated callback function.
       */
      const makeCallback = (promise, metadata) => {
        return (...callbackArgs) => {
          if (extensionAPIs.runtime.lastError) {
            promise.reject(extensionAPIs.runtime.lastError)
          } else if (metadata.singleCallbackArg || callbackArgs.length <= 1 && metadata.singleCallbackArg !== false) {
            promise.resolve(callbackArgs[0])
          } else {
            promise.resolve(callbackArgs)
          }
        }
      }

      const pluralizeArguments = numArgs => numArgs == 1 ? 'argument' : 'arguments'

      /**
       * Creates a wrapper function for a method with the given name and metadata.
       *
       * @param {string} name
       *        The name of the method which is being wrapped.
       * @param {object} metadata
       *        Metadata about the method being wrapped.
       * @param {integer} metadata.minArgs
       *        The minimum number of arguments which must be passed to the
       *        function. If called with fewer than this number of arguments, the
       *        wrapper will raise an exception.
       * @param {integer} metadata.maxArgs
       *        The maximum number of arguments which may be passed to the
       *        function. If called with more than this number of arguments, the
       *        wrapper will raise an exception.
       * @param {integer} metadata.maxResolvedArgs
       *        The maximum number of arguments which may be passed to the
       *        callback created by the wrapped async function.
       *
       * @returns {function(object, ...*)}
       *       The generated wrapper function.
       */
      const wrapAsyncFunction = (name, metadata) => {
        return function asyncFunctionWrapper (target, ...args) {
          if (args.length < metadata.minArgs) {
            throw new Error(`Expected at least ${metadata.minArgs} ${pluralizeArguments(metadata.minArgs)} for ${name}(), got ${args.length}`)
          }

          if (args.length > metadata.maxArgs) {
            throw new Error(`Expected at most ${metadata.maxArgs} ${pluralizeArguments(metadata.maxArgs)} for ${name}(), got ${args.length}`)
          }

          return new Promise((resolve, reject) => {
            if (metadata.fallbackToNoCallback) {
              // This API method has currently no callback on Chrome, but it return a promise on Firefox,
              // and so the polyfill will try to call it with a callback first, and it will fallback
              // to not passing the callback if the first call fails.
              try {
                target[name](...args, makeCallback({ resolve, reject }, metadata))
              } catch (cbError) {
                console.warn(`${name} API method doesn't seem to support the callback parameter, ` + 'falling back to call it without a callback: ', cbError)

                target[name](...args)

                // Update the API method metadata, so that the next API calls will not try to
                // use the unsupported callback anymore.
                metadata.fallbackToNoCallback = false
                metadata.noCallback = true

                resolve()
              }
            } else if (metadata.noCallback) {
              target[name](...args)
              resolve()
            } else {
              target[name](...args, makeCallback({ resolve, reject }, metadata))
            }
          })
        }
      }

      /**
       * Wraps an existing method of the target object, so that calls to it are
       * intercepted by the given wrapper function. The wrapper function receives,
       * as its first argument, the original `target` object, followed by each of
       * the arguments passed to the original method.
       *
       * @param {object} target
       *        The original target object that the wrapped method belongs to.
       * @param {function} method
       *        The method being wrapped. This is used as the target of the Proxy
       *        object which is created to wrap the method.
       * @param {function} wrapper
       *        The wrapper function which is called in place of a direct invocation
       *        of the wrapped method.
       *
       * @returns {Proxy<function>}
       *        A Proxy object for the given method, which invokes the given wrapper
       *        method in its place.
       */
      const wrapMethod = (target, method, wrapper) => {
        return new Proxy(method, {
          apply (targetMethod, thisObj, args) {
            return wrapper.call(thisObj, target, ...args)
          }
        })
      }

      const hasOwnProperty = Function.call.bind(Object.prototype.hasOwnProperty)

      /**
       * Wraps an object in a Proxy which intercepts and wraps certain methods
       * based on the given `wrappers` and `metadata` objects.
       *
       * @param {object} target
       *        The target object to wrap.
       *
       * @param {object} [wrappers = {}]
       *        An object tree containing wrapper functions for special cases. Any
       *        function present in this object tree is called in place of the
       *        method in the same location in the `target` object tree. These
       *        wrapper methods are invoked as described in {@see wrapMethod}.
       *
       * @param {object} [metadata = {}]
       *        An object tree containing metadata used to automatically generate
       *        Promise-based wrapper functions for asynchronous. Any function in
       *        the `target` object tree which has a corresponding metadata object
       *        in the same location in the `metadata` tree is replaced with an
       *        automatically-generated wrapper function, as described in
       *        {@see wrapAsyncFunction}
       *
       * @returns {Proxy<object>}
       */
      const wrapObject = (target, wrappers = {}, metadata = {}) => {
        const cache = Object.create(null)
        const handlers = {
          has (proxyTarget, prop) {
            return prop in target || prop in cache
          },

          get (proxyTarget, prop, receiver) {
            if (prop in cache) {
              return cache[prop]
            }

            if (!(prop in target)) {
              return undefined
            }

            let value = target[prop]

            if (typeof value === 'function') {
              // This is a method on the underlying object. Check if we need to do
              // any wrapping.

              if (typeof wrappers[prop] === 'function') {
                // We have a special-case wrapper for this method.
                value = wrapMethod(target, target[prop], wrappers[prop])
              } else if (hasOwnProperty(metadata, prop)) {
                // This is an async method that we have metadata for. Create a
                // Promise wrapper for it.
                const wrapper = wrapAsyncFunction(prop, metadata[prop])
                value = wrapMethod(target, target[prop], wrapper)
              } else {
                // This is a method that we don't know or care about. Return the
                // original method, bound to the underlying object.
                value = value.bind(target)
              }
            } else if (typeof value === 'object' && value !== null && (hasOwnProperty(wrappers, prop) || hasOwnProperty(metadata, prop))) {
              // This is an object that we need to do some wrapping for the children
              // of. Create a sub-object wrapper for it with the appropriate child
              // metadata.
              value = wrapObject(value, wrappers[prop], metadata[prop])
            } else {
              // We don't need to do any wrapping for this property,
              // so just forward all access to the underlying object.
              Object.defineProperty(cache, prop, {
                configurable: true,
                enumerable: true,
                get () {
                  return target[prop]
                },
                set (value) {
                  target[prop] = value
                }
              })

              return value
            }

            cache[prop] = value
            return value
          },

          set (proxyTarget, prop, value, receiver) {
            if (prop in cache) {
              cache[prop] = value
            } else {
              target[prop] = value
            }
            return true
          },

          defineProperty (proxyTarget, prop, desc) {
            return Reflect.defineProperty(cache, prop, desc)
          },

          deleteProperty (proxyTarget, prop) {
            return Reflect.deleteProperty(cache, prop)
          }
        }

        // Per contract of the Proxy API, the "get" proxy handler must return the
        // original value of the target if that value is declared read-only and
        // non-configurable. For this reason, we create an object with the
        // prototype set to `target` instead of using `target` directly.
        // Otherwise we cannot return a custom object for APIs that
        // are declared read-only and non-configurable, such as `chrome.devtools`.
        //
        // The proxy handlers themselves will still use the original `target`
        // instead of the `proxyTarget`, so that the methods and properties are
        // dereferenced via the original targets.
        const proxyTarget = Object.create(target)
        return new Proxy(proxyTarget, handlers)
      }

      /**
       * Creates a set of wrapper functions for an event object, which handles
       * wrapping of listener functions that those messages are passed.
       *
       * A single wrapper is created for each listener function, and stored in a
       * map. Subsequent calls to `addListener`, `hasListener`, or `removeListener`
       * retrieve the original wrapper, so that  attempts to remove a
       * previously-added listener work as expected.
       *
       * @param {DefaultWeakMap<function, function>} wrapperMap
       *        A DefaultWeakMap object which will create the appropriate wrapper
       *        for a given listener function when one does not exist, and retrieve
       *        an existing one when it does.
       *
       * @returns {object}
       */
      const wrapEvent = wrapperMap => ({
        addListener (target, listener, ...args) {
          target.addListener(wrapperMap.get(listener), ...args)
        },

        hasListener (target, listener) {
          return target.hasListener(wrapperMap.get(listener))
        },

        removeListener (target, listener) {
          target.removeListener(wrapperMap.get(listener))
        }
      })

      // Keep track if the deprecation warning has been logged at least once.
      let loggedSendResponseDeprecationWarning = false

      const onMessageWrappers = new DefaultWeakMap(listener => {
        if (typeof listener !== 'function') {
          return listener
        }

        /**
         * Wraps a message listener function so that it may send responses based on
         * its return value, rather than by returning a sentinel value and calling a
         * callback. If the listener function returns a Promise, the response is
         * sent when the promise either resolves or rejects.
         *
         * @param {*} message
         *        The message sent by the other end of the channel.
         * @param {object} sender
         *        Details about the sender of the message.
         * @param {function(*)} sendResponse
         *        A callback which, when called with an arbitrary argument, sends
         *        that value as a response.
         * @returns {boolean}
         *        True if the wrapped listener returned a Promise, which will later
         *        yield a response. False otherwise.
         */
        return function onMessage (message, sender, sendResponse) {
          let didCallSendResponse = false

          let wrappedSendResponse
          const sendResponsePromise = new Promise(resolve => {
            wrappedSendResponse = function (response) {
              if (!loggedSendResponseDeprecationWarning) {
                console.warn(SEND_RESPONSE_DEPRECATION_WARNING, new Error().stack)
                loggedSendResponseDeprecationWarning = true
              }
              didCallSendResponse = true
              resolve(response)
            }
          })

          let result
          try {
            result = listener(message, sender, wrappedSendResponse)
          } catch (err) {
            result = Promise.reject(err)
          }

          const isResultThenable = result !== true && isThenable(result)

          // If the listener didn't returned true or a Promise, or called
          // wrappedSendResponse synchronously, we can exit earlier
          // because there will be no response sent from this listener.
          if (result !== true && !isResultThenable && !didCallSendResponse) {
            return false
          }

          // A small helper to send the message if the promise resolves
          // and an error if the promise rejects (a wrapped sendMessage has
          // to translate the message into a resolved promise or a rejected
          // promise).
          const sendPromisedResult = promise => {
            promise.then(msg => {
              // send the message value.
              sendResponse(msg)
            }, error => {
              // Send a JSON representation of the error if the rejected value
              // is an instance of error, or the object itself otherwise.
              let message
              if (error && (error instanceof Error || typeof error.message === 'string')) {
                message = error.message
              } else {
                message = 'An unexpected error occurred'
              }

              sendResponse({
                __mozWebExtensionPolyfillReject__: true,
                message
              })
            }).catch(err => {
              // Print an error on the console if unable to send the response.
              console.error('Failed to send onMessage rejected reply', err)
            })
          }

          // If the listener returned a Promise, send the resolved value as a
          // result, otherwise wait the promise related to the wrappedSendResponse
          // callback to resolve and send it as a response.
          if (isResultThenable) {
            sendPromisedResult(result)
          } else {
            sendPromisedResult(sendResponsePromise)
          }

          // Let Chrome know that the listener is replying.
          return true
        }
      })

      const wrappedSendMessageCallback = ({ reject, resolve }, reply) => {
        if (extensionAPIs.runtime.lastError) {
          // Detect when none of the listeners replied to the sendMessage call and resolve
          // the promise to undefined as in Firefox.
          // See https://github.com/mozilla/webextension-polyfill/issues/130
          if (extensionAPIs.runtime.lastError.message === CHROME_SEND_MESSAGE_CALLBACK_NO_RESPONSE_MESSAGE) {
            resolve()
          } else {
            reject(extensionAPIs.runtime.lastError)
          }
        } else if (reply && reply.__mozWebExtensionPolyfillReject__) {
          // Convert back the JSON representation of the error into
          // an Error instance.
          reject(new Error(reply.message))
        } else {
          resolve(reply)
        }
      }

      const wrappedSendMessage = (name, metadata, apiNamespaceObj, ...args) => {
        if (args.length < metadata.minArgs) {
          throw new Error(`Expected at least ${metadata.minArgs} ${pluralizeArguments(metadata.minArgs)} for ${name}(), got ${args.length}`)
        }

        if (args.length > metadata.maxArgs) {
          throw new Error(`Expected at most ${metadata.maxArgs} ${pluralizeArguments(metadata.maxArgs)} for ${name}(), got ${args.length}`)
        }

        return new Promise((resolve, reject) => {
          const wrappedCb = wrappedSendMessageCallback.bind(null, { resolve, reject })
          args.push(wrappedCb)
          apiNamespaceObj.sendMessage(...args)
        })
      }

      const staticWrappers = {
        runtime: {
          onMessage: wrapEvent(onMessageWrappers),
          onMessageExternal: wrapEvent(onMessageWrappers),
          sendMessage: wrappedSendMessage.bind(null, 'sendMessage', { minArgs: 1, maxArgs: 3 })
        },
        tabs: {
          sendMessage: wrappedSendMessage.bind(null, 'sendMessage', { minArgs: 2, maxArgs: 3 })
        }
      }
      const settingMetadata = {
        clear: { minArgs: 1, maxArgs: 1 },
        get: { minArgs: 1, maxArgs: 1 },
        set: { minArgs: 1, maxArgs: 1 }
      }
      apiMetadata.privacy = {
        network: {
          networkPredictionEnabled: settingMetadata,
          webRTCIPHandlingPolicy: settingMetadata
        },
        services: {
          passwordSavingEnabled: settingMetadata
        },
        websites: {
          hyperlinkAuditingEnabled: settingMetadata,
          referrersEnabled: settingMetadata
        }
      }

      return wrapObject(extensionAPIs, staticWrappers, apiMetadata)
    }

    if (typeof chrome !== 'object' || !chrome || !chrome.runtime || !chrome.runtime.id) {
      throw new Error('This script should only be loaded in a browser extension.')
    }

    // The build process adds a UMD wrapper around this file, which makes the
    // `module` variable available.
    module.exports = wrapAPIs(chrome)
  } else {
    module.exports = browser
  }
})
// # sourceMappingURL=browser-polyfill.js.map