DO NOT SUBMIT: what chrome/browser/resources/ could eventually look like with clang-format

chrome/browser/resources/hotword/audio_client.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 'use strict';
 
 /* eslint-disable no-restricted-properties */
 
 /**
  * @fileoverview This is the audio client content script injected into eligible
  *  Google.com and New tab pages for interaction between the Webpage and the
  *  Hotword extension.
  */
 
 (function() {
+/**
+ * @constructor
+ */
+var AudioClient = function() {
+  /** @private {Element} */
+  this.speechOverlay_ = null;
+
+  /** @private {number} */
+  this.checkSpeechUiRetries_ = 0;
+
   /**
-   * @constructor
+   * Port used to communicate with the audio manager.
+   * @private {?Port}
    */
-  var AudioClient = function() {
-    /** @private {Element} */
-    this.speechOverlay_ = null;
-
-    /** @private {number} */
+  this.port_ = null;
+
+  /**
+   * Keeps track of the effects of different commands. Used to verify that
+   * proper UIs are shown to the user.
+   * @private {Object<AudioClient.CommandToPage, Object>}
+   */
+  this.uiStatus_ = null;
+
+  /**
+   * Bound function used to handle commands sent from the page to this script.
+   * @private {Function}
+   */
+  this.handleCommandFromPageFunc_ = null;
+};
+
+/**
+ * Messages sent to the page to control the voice search UI.
+ * @enum {string}
+ */
+AudioClient.CommandToPage = {
+  HOTWORD_VOICE_TRIGGER: 'vt',
+  HOTWORD_STARTED: 'hs',
+  HOTWORD_ENDED: 'hd',
+  HOTWORD_TIMEOUT: 'ht',
+  HOTWORD_ERROR: 'he'
+};
+
+/**
+ * Messages received from the page used to indicate voice search state.
+ * @enum {string}
+ */
+AudioClient.CommandFromPage = {
+  SPEECH_START: 'ss',
+  SPEECH_END: 'se',
+  SPEECH_RESET: 'sr',
+  SHOWING_HOTWORD_START: 'shs',
+  SHOWING_ERROR_MESSAGE: 'sem',
+  SHOWING_TIMEOUT_MESSAGE: 'stm',
+  CLICKED_RESUME: 'hcc',
+  CLICKED_RESTART: 'hcr',
+  CLICKED_DEBUG: 'hcd'
+};
+
+/**
+ * Errors that are sent to the hotword extension.
+ * @enum {string}
+ */
+AudioClient.Error = {
+  NO_SPEECH_UI: 'ac1',
+  NO_HOTWORD_STARTED_UI: 'ac2',
+  NO_HOTWORD_TIMEOUT_UI: 'ac3',
+  NO_HOTWORD_ERROR_UI: 'ac4'
+};
+
+/**
+ * @const {string}
+ * @private
+ */
+AudioClient.HOTWORD_EXTENSION_ID_ = 'nbpagnldghgfoolbancepceaanlmhfmd';
+
+/**
+ * Number of times to retry checking a transient error.
+ * @const {number}
+ * @private
+ */
+AudioClient.MAX_RETRIES = 3;
+
+/**
+ * Delay to wait in milliseconds before rechecking for any transient errors.
+ * @const {number}
+ * @private
+ */
+AudioClient.RETRY_TIME_MS_ = 2000;
+
+/**
+ * DOM ID for the speech UI overlay.
+ * @const {string}
+ * @private
+ */
+AudioClient.SPEECH_UI_OVERLAY_ID_ = 'spch';
+
+/**
+ * @const {string}
+ * @private
+ */
+AudioClient.HELP_CENTER_URL_ =
+    'https://support.google.com/chrome/?p=ui_hotword_search';
+
+/**
+ * @const {string}
+ * @private
+ */
+AudioClient.CLIENT_PORT_NAME_ = 'chwcpn';
+
+/**
+ * Existence of the Audio Client.
+ * @const {string}
+ * @private
+ */
+AudioClient.EXISTS_ = 'chwace';
+
+/**
+ * Checks for the presence of speech overlay UI DOM elements.
+ * @private
+ */
+AudioClient.prototype.checkSpeechOverlayUi_ = function() {
+  if (!this.speechOverlay_) {
+    window.setTimeout(
+        this.delayedCheckSpeechOverlayUi_.bind(this),
+        AudioClient.RETRY_TIME_MS_);
+  } else {
     this.checkSpeechUiRetries_ = 0;
-
-    /**
-     * Port used to communicate with the audio manager.
-     * @private {?Port}
-     */
-    this.port_ = null;
-
-    /**
-     * Keeps track of the effects of different commands. Used to verify that
-     * proper UIs are shown to the user.
-     * @private {Object<AudioClient.CommandToPage, Object>}
-     */
-    this.uiStatus_ = null;
-
-    /**
-     * Bound function used to handle commands sent from the page to this script.
-     * @private {Function}
-     */
-    this.handleCommandFromPageFunc_ = null;
+  }
+};
+
+/**
+ * Function called to check for the speech UI overlay after some time has
+ * passed since an initial check. Will either retry triggering the speech
+ * or sends an error message depending on the number of retries.
+ * @private
+ */
+AudioClient.prototype.delayedCheckSpeechOverlayUi_ = function() {
+  this.speechOverlay_ =
+      document.getElementById(AudioClient.SPEECH_UI_OVERLAY_ID_);
+  if (!this.speechOverlay_) {
+    if (this.checkSpeechUiRetries_++ < AudioClient.MAX_RETRIES) {
+      this.sendCommandToPage_(AudioClient.CommandToPage.VOICE_TRIGGER);
+      this.checkSpeechOverlayUi_();
+    } else {
+      this.sendCommandToExtension_(AudioClient.Error.NO_SPEECH_UI);
+    }
+  } else {
+    this.checkSpeechUiRetries_ = 0;
+  }
+};
+
+/**
+ * Checks that the triggered UI is actually displayed.
+ * @param {AudioClient.CommandToPage} command Command that was send.
+ * @private
+ */
+AudioClient.prototype.checkUi_ = function(command) {
+  this.uiStatus_[command].timeoutId = window.setTimeout(
+      this.failedCheckUi_.bind(this, command), AudioClient.RETRY_TIME_MS_);
+};
+
+/**
+ * Function called when the UI verification is not called in time. Will either
+ * retry the command or sends an error message, depending on the number of
+ * retries for the command.
+ * @param {AudioClient.CommandToPage} command Command that was sent.
+ * @private
+ */
+AudioClient.prototype.failedCheckUi_ = function(command) {
+  if (this.uiStatus_[command].tries++ < AudioClient.MAX_RETRIES) {
+    this.sendCommandToPage_(command);
+    this.checkUi_(command);
+  } else {
+    this.sendCommandToExtension_(this.uiStatus_[command].error);
+  }
+};
+
+/**
+ * Confirm that an UI element has been shown.
+ * @param {AudioClient.CommandToPage} command UI to confirm.
+ * @private
+ */
+AudioClient.prototype.verifyUi_ = function(command) {
+  if (this.uiStatus_[command].timeoutId) {
+    window.clearTimeout(this.uiStatus_[command].timeoutId);
+    this.uiStatus_[command].timeoutId = null;
+    this.uiStatus_[command].tries = 0;
+  }
+};
+
+/**
+ * Sends a command to the audio manager.
+ * @param {string} commandStr command to send to plugin.
+ * @private
+ */
+AudioClient.prototype.sendCommandToExtension_ = function(commandStr) {
+  if (this.port_)
+    this.port_.postMessage({'cmd': commandStr});
+};
+
+/**
+ * Handles a message from the audio manager.
+ * @param {{cmd: string}} commandObj Command from the audio manager.
+ * @private
+ */
+AudioClient.prototype.handleCommandFromExtension_ = function(commandObj) {
+  var command = commandObj['cmd'];
+  if (command) {
+    switch (command) {
+      case AudioClient.CommandToPage.HOTWORD_VOICE_TRIGGER:
+        this.sendCommandToPage_(command);
+        this.checkSpeechOverlayUi_();
+        break;
+      case AudioClient.CommandToPage.HOTWORD_STARTED:
+        this.sendCommandToPage_(command);
+        this.checkUi_(command);
+        break;
+      case AudioClient.CommandToPage.HOTWORD_ENDED:
+        this.sendCommandToPage_(command);
+        break;
+      case AudioClient.CommandToPage.HOTWORD_TIMEOUT:
+        this.sendCommandToPage_(command);
+        this.checkUi_(command);
+        break;
+      case AudioClient.CommandToPage.HOTWORD_ERROR:
+        this.sendCommandToPage_(command);
+        this.checkUi_(command);
+        break;
+    }
+  }
+};
+
+/**
+ * @param {AudioClient.CommandToPage} commandStr Command to send.
+ * @private
+ */
+AudioClient.prototype.sendCommandToPage_ = function(commandStr) {
+  window.postMessage({'type': commandStr}, '*');
+};
+
+/**
+ * Handles a message from the html window.
+ * @param {!MessageEvent} messageEvent Message event from the window.
+ * @private
+ */
+AudioClient.prototype.handleCommandFromPage_ = function(messageEvent) {
+  if (messageEvent.source == window && messageEvent.data.type) {
+    var command = messageEvent.data.type;
+    switch (command) {
+      case AudioClient.CommandFromPage.SPEECH_START:
+        this.speechActive_ = true;
+        this.sendCommandToExtension_(command);
+        break;
+      case AudioClient.CommandFromPage.SPEECH_END:
+        this.speechActive_ = false;
+        this.sendCommandToExtension_(command);
+        break;
+      case AudioClient.CommandFromPage.SPEECH_RESET:
+        this.speechActive_ = false;
+        this.sendCommandToExtension_(command);
+        break;
+      case 'SPEECH_RESET':  // Legacy, for embedded NTP.
+        this.speechActive_ = false;
+        this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_END);
+        break;
+      case AudioClient.CommandFromPage.CLICKED_RESUME:
+        this.sendCommandToExtension_(command);
+        break;
+      case AudioClient.CommandFromPage.CLICKED_RESTART:
+        this.sendCommandToExtension_(command);
+        break;
+      case AudioClient.CommandFromPage.CLICKED_DEBUG:
+        window.open(AudioClient.HELP_CENTER_URL_, '_blank');
+        break;
+      case AudioClient.CommandFromPage.SHOWING_HOTWORD_START:
+        this.verifyUi_(AudioClient.CommandToPage.HOTWORD_STARTED);
+        break;
+      case AudioClient.CommandFromPage.SHOWING_ERROR_MESSAGE:
+        this.verifyUi_(AudioClient.CommandToPage.HOTWORD_ERROR);
+        break;
+      case AudioClient.CommandFromPage.SHOWING_TIMEOUT_MESSAGE:
+        this.verifyUi_(AudioClient.CommandToPage.HOTWORD_TIMEOUT);
+        break;
+    }
+  }
+};
+
+/**
+ * Initialize the content script.
+ */
+AudioClient.prototype.initialize = function() {
+  if (AudioClient.EXISTS_ in window)
+    return;
+  window[AudioClient.EXISTS_] = true;
+
+  // UI verification object.
+  this.uiStatus_ = {};
+  this.uiStatus_[AudioClient.CommandToPage.HOTWORD_STARTED] = {
+    timeoutId: null,
+    tries: 0,
+    error: AudioClient.Error.NO_HOTWORD_STARTED_UI
   };
-
-  /**
-   * Messages sent to the page to control the voice search UI.
-   * @enum {string}
-   */
-  AudioClient.CommandToPage = {
-    HOTWORD_VOICE_TRIGGER: 'vt',
-    HOTWORD_STARTED: 'hs',
-    HOTWORD_ENDED: 'hd',
-    HOTWORD_TIMEOUT: 'ht',
-    HOTWORD_ERROR: 'he'
+  this.uiStatus_[AudioClient.CommandToPage.HOTWORD_TIMEOUT] = {
+    timeoutId: null,
+    tries: 0,
+    error: AudioClient.Error.NO_HOTWORD_TIMEOUT_UI
   };
-
-  /**
-   * Messages received from the page used to indicate voice search state.
-   * @enum {string}
-   */
-  AudioClient.CommandFromPage = {
-    SPEECH_START: 'ss',
-    SPEECH_END: 'se',
-    SPEECH_RESET: 'sr',
-    SHOWING_HOTWORD_START: 'shs',
-    SHOWING_ERROR_MESSAGE: 'sem',
-    SHOWING_TIMEOUT_MESSAGE: 'stm',
-    CLICKED_RESUME: 'hcc',
-    CLICKED_RESTART: 'hcr',
-    CLICKED_DEBUG: 'hcd'
+  this.uiStatus_[AudioClient.CommandToPage.HOTWORD_ERROR] = {
+    timeoutId: null,
+    tries: 0,
+    error: AudioClient.Error.NO_HOTWORD_ERROR_UI
   };
 
-  /**
-   * Errors that are sent to the hotword extension.
-   * @enum {string}
-   */
-  AudioClient.Error = {
-    NO_SPEECH_UI: 'ac1',
-    NO_HOTWORD_STARTED_UI: 'ac2',
-    NO_HOTWORD_TIMEOUT_UI: 'ac3',
-    NO_HOTWORD_ERROR_UI: 'ac4'
-  };
-
-  /**
-   * @const {string}
-   * @private
-   */
-  AudioClient.HOTWORD_EXTENSION_ID_ = 'nbpagnldghgfoolbancepceaanlmhfmd';
-
-  /**
-   * Number of times to retry checking a transient error.
-   * @const {number}
-   * @private
-   */
-  AudioClient.MAX_RETRIES = 3;
-
-  /**
-   * Delay to wait in milliseconds before rechecking for any transient errors.
-   * @const {number}
-   * @private
-   */
-  AudioClient.RETRY_TIME_MS_ = 2000;
-
-  /**
-   * DOM ID for the speech UI overlay.
-   * @const {string}
-   * @private
-   */
-  AudioClient.SPEECH_UI_OVERLAY_ID_ = 'spch';
-
-  /**
-   * @const {string}
-   * @private
-   */
-  AudioClient.HELP_CENTER_URL_ =
-      'https://support.google.com/chrome/?p=ui_hotword_search';
-
-  /**
-   * @const {string}
-   * @private
-   */
-  AudioClient.CLIENT_PORT_NAME_ = 'chwcpn';
-
-  /**
-   * Existence of the Audio Client.
-   * @const {string}
-   * @private
-   */
-  AudioClient.EXISTS_ = 'chwace';
-
-  /**
-   * Checks for the presence of speech overlay UI DOM elements.
-   * @private
-   */
-  AudioClient.prototype.checkSpeechOverlayUi_ = function() {
-    if (!this.speechOverlay_) {
-      window.setTimeout(
-          this.delayedCheckSpeechOverlayUi_.bind(this),
-          AudioClient.RETRY_TIME_MS_);
-    } else {
-      this.checkSpeechUiRetries_ = 0;
-    }
-  };
-
-  /**
-   * Function called to check for the speech UI overlay after some time has
-   * passed since an initial check. Will either retry triggering the speech
-   * or sends an error message depending on the number of retries.
-   * @private
-   */
-  AudioClient.prototype.delayedCheckSpeechOverlayUi_ = function() {
-    this.speechOverlay_ =
-        document.getElementById(AudioClient.SPEECH_UI_OVERLAY_ID_);
-    if (!this.speechOverlay_) {
-      if (this.checkSpeechUiRetries_++ < AudioClient.MAX_RETRIES) {
-        this.sendCommandToPage_(AudioClient.CommandToPage.VOICE_TRIGGER);
-        this.checkSpeechOverlayUi_();
-      } else {
-        this.sendCommandToExtension_(AudioClient.Error.NO_SPEECH_UI);
-      }
-    } else {
-      this.checkSpeechUiRetries_ = 0;
-    }
-  };
-
-  /**
-   * Checks that the triggered UI is actually displayed.
-   * @param {AudioClient.CommandToPage} command Command that was send.
-   * @private
-   */
-  AudioClient.prototype.checkUi_ = function(command) {
-    this.uiStatus_[command].timeoutId = window.setTimeout(
-        this.failedCheckUi_.bind(this, command), AudioClient.RETRY_TIME_MS_);
-  };
-
-  /**
-   * Function called when the UI verification is not called in time. Will either
-   * retry the command or sends an error message, depending on the number of
-   * retries for the command.
-   * @param {AudioClient.CommandToPage} command Command that was sent.
-   * @private
-   */
-  AudioClient.prototype.failedCheckUi_ = function(command) {
-    if (this.uiStatus_[command].tries++ < AudioClient.MAX_RETRIES) {
-      this.sendCommandToPage_(command);
-      this.checkUi_(command);
-    } else {
-      this.sendCommandToExtension_(this.uiStatus_[command].error);
-    }
-  };
-
-  /**
-   * Confirm that an UI element has been shown.
-   * @param {AudioClient.CommandToPage} command UI to confirm.
-   * @private
-   */
-  AudioClient.prototype.verifyUi_ = function(command) {
-    if (this.uiStatus_[command].timeoutId) {
-      window.clearTimeout(this.uiStatus_[command].timeoutId);
-      this.uiStatus_[command].timeoutId = null;
-      this.uiStatus_[command].tries = 0;
-    }
-  };
-
-  /**
-   * Sends a command to the audio manager.
-   * @param {string} commandStr command to send to plugin.
-   * @private
-   */
-  AudioClient.prototype.sendCommandToExtension_ = function(commandStr) {
-    if (this.port_)
-      this.port_.postMessage({'cmd': commandStr});
-  };
-
-  /**
-   * Handles a message from the audio manager.
-   * @param {{cmd: string}} commandObj Command from the audio manager.
-   * @private
-   */
-  AudioClient.prototype.handleCommandFromExtension_ = function(commandObj) {
-    var command = commandObj['cmd'];
-    if (command) {
-      switch (command) {
-        case AudioClient.CommandToPage.HOTWORD_VOICE_TRIGGER:
-          this.sendCommandToPage_(command);
-          this.checkSpeechOverlayUi_();
-          break;
-        case AudioClient.CommandToPage.HOTWORD_STARTED:
-          this.sendCommandToPage_(command);
-          this.checkUi_(command);
-          break;
-        case AudioClient.CommandToPage.HOTWORD_ENDED:
-          this.sendCommandToPage_(command);
-          break;
-        case AudioClient.CommandToPage.HOTWORD_TIMEOUT:
-          this.sendCommandToPage_(command);
-          this.checkUi_(command);
-          break;
-        case AudioClient.CommandToPage.HOTWORD_ERROR:
-          this.sendCommandToPage_(command);
-          this.checkUi_(command);
-          break;
-      }
-    }
-  };
-
-  /**
-   * @param {AudioClient.CommandToPage} commandStr Command to send.
-   * @private
-   */
-  AudioClient.prototype.sendCommandToPage_ = function(commandStr) {
-    window.postMessage({'type': commandStr}, '*');
-  };
-
-  /**
-   * Handles a message from the html window.
-   * @param {!MessageEvent} messageEvent Message event from the window.
-   * @private
-   */
-  AudioClient.prototype.handleCommandFromPage_ = function(messageEvent) {
-    if (messageEvent.source == window && messageEvent.data.type) {
-      var command = messageEvent.data.type;
-      switch (command) {
-        case AudioClient.CommandFromPage.SPEECH_START:
-          this.speechActive_ = true;
-          this.sendCommandToExtension_(command);
-          break;
-        case AudioClient.CommandFromPage.SPEECH_END:
-          this.speechActive_ = false;
-          this.sendCommandToExtension_(command);
-          break;
-        case AudioClient.CommandFromPage.SPEECH_RESET:
-          this.speechActive_ = false;
-          this.sendCommandToExtension_(command);
-          break;
-        case 'SPEECH_RESET':  // Legacy, for embedded NTP.
-          this.speechActive_ = false;
-          this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_END);
-          break;
-        case AudioClient.CommandFromPage.CLICKED_RESUME:
-          this.sendCommandToExtension_(command);
-          break;
-        case AudioClient.CommandFromPage.CLICKED_RESTART:
-          this.sendCommandToExtension_(command);
-          break;
-        case AudioClient.CommandFromPage.CLICKED_DEBUG:
-          window.open(AudioClient.HELP_CENTER_URL_, '_blank');
-          break;
-        case AudioClient.CommandFromPage.SHOWING_HOTWORD_START:
-          this.verifyUi_(AudioClient.CommandToPage.HOTWORD_STARTED);
-          break;
-        case AudioClient.CommandFromPage.SHOWING_ERROR_MESSAGE:
-          this.verifyUi_(AudioClient.CommandToPage.HOTWORD_ERROR);
-          break;
-        case AudioClient.CommandFromPage.SHOWING_TIMEOUT_MESSAGE:
-          this.verifyUi_(AudioClient.CommandToPage.HOTWORD_TIMEOUT);
-          break;
-      }
-    }
-  };
-
-  /**
-   * Initialize the content script.
-   */
-  AudioClient.prototype.initialize = function() {
-    if (AudioClient.EXISTS_ in window)
-      return;
-    window[AudioClient.EXISTS_] = true;
-
-    // UI verification object.
-    this.uiStatus_ = {};
-    this.uiStatus_[AudioClient.CommandToPage.HOTWORD_STARTED] = {
-      timeoutId: null,
-      tries: 0,
-      error: AudioClient.Error.NO_HOTWORD_STARTED_UI
-    };
-    this.uiStatus_[AudioClient.CommandToPage.HOTWORD_TIMEOUT] = {
-      timeoutId: null,
-      tries: 0,
-      error: AudioClient.Error.NO_HOTWORD_TIMEOUT_UI
-    };
-    this.uiStatus_[AudioClient.CommandToPage.HOTWORD_ERROR] = {
-      timeoutId: null,
-      tries: 0,
-      error: AudioClient.Error.NO_HOTWORD_ERROR_UI
-    };
-
-    this.handleCommandFromPageFunc_ = this.handleCommandFromPage_.bind(this);
-    window.addEventListener('message', this.handleCommandFromPageFunc_, false);
-    this.initPort_();
-  };
-
-  /**
-   * Initialize the communications port with the audio manager. This
-   * function will be also be called again if the audio-manager
-   * disconnects for some reason (such as the extension
-   * background.html page being reloaded).
-   * @private
-   */
-  AudioClient.prototype.initPort_ = function() {
-    this.port_ = chrome.runtime.connect(
-        AudioClient.HOTWORD_EXTENSION_ID_,
-        {'name': AudioClient.CLIENT_PORT_NAME_});
-    // Note that this listen may have to be destroyed manually if AudioClient
-    // is ever destroyed on this tab.
-    this.port_.onDisconnect.addListener(
-        (function(e) {
-          if (this.handleCommandFromPageFunc_) {
-            window.removeEventListener(
-                'message', this.handleCommandFromPageFunc_, false);
-          }
-          delete window[AudioClient.EXISTS_];
-        }).bind(this));
-
-    // See note above.
-    this.port_.onMessage.addListener(
-        this.handleCommandFromExtension_.bind(this));
-
-    if (this.speechActive_) {
-      this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_START);
-    } else {
-      // It's possible for this script to be injected into the page after it has
-      // completed loaded (i.e. when prerendering). In this case, this script
-      // won't receive a SPEECH_RESET from the page to forward onto the
-      // extension. To make up for this, always send a SPEECH_RESET. This means
-      // in most cases, the extension will receive SPEECH_RESET twice, one from
-      // this sendCommandToExtension_ and the one forwarded from the page. But
-      // that's OK and the extension can handle it.
-      this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_RESET);
-    }
-  };
-
-  // Initializes as soon as the code is ready, do not wait for the page.
-  new AudioClient().initialize();
+  this.handleCommandFromPageFunc_ = this.handleCommandFromPage_.bind(this);
+  window.addEventListener('message', this.handleCommandFromPageFunc_, false);
+  this.initPort_();
+};
+
+/**
+ * Initialize the communications port with the audio manager. This
+ * function will be also be called again if the audio-manager
+ * disconnects for some reason (such as the extension
+ * background.html page being reloaded).
+ * @private
+ */
+AudioClient.prototype.initPort_ = function() {
+  this.port_ = chrome.runtime.connect(
+      AudioClient.HOTWORD_EXTENSION_ID_,
+      {'name': AudioClient.CLIENT_PORT_NAME_});
+  // Note that this listen may have to be destroyed manually if AudioClient
+  // is ever destroyed on this tab.
+  this.port_.onDisconnect.addListener(
+      (function(e) {
+        if (this.handleCommandFromPageFunc_) {
+          window.removeEventListener(
+              'message', this.handleCommandFromPageFunc_, false);
+        }
+        delete window[AudioClient.EXISTS_];
+      }).bind(this));
+
+  // See note above.
+  this.port_.onMessage.addListener(this.handleCommandFromExtension_.bind(this));
+
+  if (this.speechActive_) {
+    this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_START);
+  } else {
+    // It's possible for this script to be injected into the page after it has
+    // completed loaded (i.e. when prerendering). In this case, this script
+    // won't receive a SPEECH_RESET from the page to forward onto the
+    // extension. To make up for this, always send a SPEECH_RESET. This means
+    // in most cases, the extension will receive SPEECH_RESET twice, one from
+    // this sendCommandToExtension_ and the one forwarded from the page. But
+    // that's OK and the extension can handle it.
+    this.sendCommandToExtension_(AudioClient.CommandFromPage.SPEECH_RESET);
+  }
+};
+
+// Initializes as soon as the code is ready, do not wait for the page.
+new AudioClient().initialize();
 })();