Add new hotword extension for built-in hotword triggering.

This is just a skeleton of the extension and doesn't have any functionality.

Can't use the existing hotword_helper since this has a hard dependency
on a shared module (which doesn't yet exist).

BUG=397019

Review URL: https://codereview.chromium.org/423083002

Cr-Commit-Position: refs/heads/master@{#288956}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288956 0039d316-1c4b-4281-b951-d872f2087c98

WATCHLISTS

@@ -358,6 +358,7 @@
     'hotword': {
       'filepath': 'chrome/browser/extensions/api/hotword_private/'\
                   '|chrome/browser/resources/hotword_helper/'\
+                  '|chrome/browser/resources/hotword/'\
                   '|chrome/browser/search/hotword*'\
                   '|chrome/test/data/extensions/api_test/hotword_private/',
     },

chrome/browser/browser_resources.grd

@@ -155,6 +155,7 @@
         <include name="IDR_HANGOUT_SERVICES_MANIFEST" file="resources\hangout_services\manifest.json" type="BINDATA" />
       </if>
       <include name="IDR_HOTWORD_HELPER_MANIFEST" file="resources\hotword_helper\manifest.json" type="BINDATA" />
+      <include name="IDR_HOTWORD_MANIFEST" file="resources\hotword\manifest.json" type="BINDATA" />
       <if expr="not is_android">
         <include name="IDR_HELP_JS" file="resources\help\help.js" flattenhtml="true" type="BINDATA" />
         <include name="IDR_HELP_PAGE_JS" file="resources\help\help_page.js" flattenhtml="true" type="BINDATA" />

chrome/browser/extensions/component_loader.cc

@@ -304,8 +304,14 @@ void ComponentLoader::AddHangoutServicesExtension() {
 
 void ComponentLoader::AddHotwordHelperExtension() {
   if (HotwordServiceFactory::IsHotwordAllowed(browser_context_)) {
-    Add(IDR_HOTWORD_HELPER_MANIFEST,
-        base::FilePath(FILE_PATH_LITERAL("hotword_helper")));
+    CommandLine* command_line = CommandLine::ForCurrentProcess();
+    if (command_line->HasSwitch(switches::kEnableExperimentalHotwording)) {
+      Add(IDR_HOTWORD_MANIFEST,
+          base::FilePath(FILE_PATH_LITERAL("hotword")));
+    } else {
+      Add(IDR_HOTWORD_HELPER_MANIFEST,
+          base::FilePath(FILE_PATH_LITERAL("hotword_helper")));
+    }
   }
 }
 

chrome/browser/extensions/external_component_loader.cc

@@ -4,13 +4,19 @@
 
 #include "chrome/browser/extensions/external_component_loader.h"
 
+#include "base/command_line.h"
 #include "chrome/browser/bookmarks/enhanced_bookmarks_features.h"
 #include "chrome/browser/browser_process.h"
-#include "chrome/browser/search/hotword_service_factory.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "components/signin/core/browser/signin_manager.h"
 
+// TODO(thestig): Remove after extensions are disabled on mobile.
+#if defined(ENABLE_EXTENSIONS)
+#include "chrome/browser/search/hotword_service_factory.h"
+#endif
+
 namespace {
 
 bool IsUserSignedin(Profile* profile) {
@@ -34,11 +40,18 @@ void ExternalComponentLoader::StartLoading() {
   prefs_->SetString(appId + ".external_update_url",
                     extension_urls::GetWebstoreUpdateUrl().spec());
 
+#if defined(ENABLE_EXTENSIONS)
   if (HotwordServiceFactory::IsHotwordAllowed(profile_)) {
     std::string hotwordId = extension_misc::kHotwordExtensionId;
-    prefs_->SetString(hotwordId + ".external_update_url",
-                      extension_urls::GetWebstoreUpdateUrl().spec());
+    CommandLine* command_line = CommandLine::ForCurrentProcess();
+    // TODO(amistry): Load the hotword shared module when enabling built-in
+    // hotword detection.
+    if (!command_line->HasSwitch(switches::kEnableExperimentalHotwording)) {
+      prefs_->SetString(hotwordId + ".external_update_url",
+                        extension_urls::GetWebstoreUpdateUrl().spec());
+    }
   }
+#endif
 
   UpdateBookmarksExperimentState(
       profile_->GetPrefs(),

chrome/browser/resources/component_extension_resources.grd

@@ -58,10 +58,13 @@
         <include name="IDR_HANGOUT_SERVICES_BACKGROUND_HTML" file="hangout_services/background.html" type="BINDATA" />
         <include name="IDR_HANGOUT_SERVICES_THUNK_JS" file="hangout_services/thunk.js" type="BINDATA" />
       </if>
-      <!-- Hotword Helper extension -->
       <if expr="enable_extensions">
+        <!-- Hotword Helper extension -->
         <include name="IDR_HOTWORD_HELPER_AUDIO_CLIENT_JS" file="hotword_helper/audio_client.js" type="BINDATA" />
         <include name="IDR_HOTWORD_HELPER_MANAGER_JS" file="hotword_helper/manager.js" type="BINDATA" />
+
+        <!-- (Experimental) hotword triggering extension -->
+        <include name="IDR_HOTWORD_MANAGER_JS" file="hotword/manager.js" type="BINDATA" />
       </if>
       <if expr="not is_android">
         <include name="IDR_FEEDBACK_DEFAULT_HTML" file="feedback/html/default.html" flattenhtml="true" allowexternalscript="true" type="BINDATA" />

chrome/browser/resources/hotword/manager.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';
+
+/**
+ * @fileoverview This extension provides hotword triggering capabilites to
+ * Chrome.
+ *
+ * This extension contains all the JavaScript for loading and managing the
+ * hotword detector. The hotword detector and language model data will be
+ * provided by a shared module loaded from the web store.
+ */
+

chrome/browser/resources/hotword/manifest.json

+{
+  // Extension ID: nbpagnldghgfoolbancepceaanlmhfmd
+  "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDbHXRPiq2De9EJ+4pvNN6uE/D2avxrqyLSpA/Hq3II+btkPl1gboY3oUPTfevpVOFa90Y1c1b3/W682dXqybT0klIvFLKhdQx0LiVqSUQyIaDrwOCSo/ZcukbEwDRojegWymCjHvX6WZk4kKZzTJYzY1vrp0TWKLhttEMN9KFmowIDAQAB",
+
+  "name": "Hotword triggering",
+  "version": "0.0.1.0",
+  "manifest_version": 2,
+
+  "background": {
+    "scripts": ["manager.js"],
+    "persistent": false
+  },
+
+  "permissions": [
+    "*://*.google.com/*",
+    "chrome://newtab/",
+    "hotwordPrivate",
+    "tabs"
+  ],
+
+  "externally_connectable": {
+    "matches": [
+      "*://*.google.com/*",
+      "chrome://newtab/"
+    ]
+  },
+
+  "import": [
+    {
+      // TODO(amistry): For now, use a locally modified version of the external
+      // hotword extension. Replace with the ID of the new shared module
+      // containing the hotword detector.
+      "id": "bepbmhgboaologfdajaanbcjmnhjmhfn"
+    }
+  ],
+
+  "minimum_chrome_version": "38"
+}