Add new hotword extension for built-in hotword triggering.

chrome/browser/extensions/external_component_loader.cc

 // Copyright (c) 2013 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.
 
 #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/signin/signin_manager_factory.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
 
+#if defined(OS_CHROMEOS)
+#include "chromeos/chromeos_switches.h"
+#endif
+
 namespace {
 
 bool IsUserSignedin(Profile* profile) {
   SigninManagerBase* signin = SigninManagerFactory::GetForProfile(profile);
   return signin && !signin->GetAuthenticatedUsername().empty();
 }
 
 }  // namespace
 
 namespace extensions {
 
 ExternalComponentLoader::ExternalComponentLoader(Profile* profile)
     : profile_(profile) {
 }
 
 ExternalComponentLoader::~ExternalComponentLoader() {}
 
 void ExternalComponentLoader::StartLoading() {
   prefs_.reset(new base::DictionaryValue());
   std::string appId = extension_misc::kInAppPaymentsSupportAppId;
   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());
+#if defined(OS_CHROMEOS)
+    CommandLine* command_line = CommandLine::ForCurrentProcess();

[James Hawkins, 2014/08/05 08:59:45]

Same as component_loader, create a ChromeOS-specific implementation instead of
using #ifdef.

+    if (command_line->HasSwitch(
+        chromeos::switches::kEnableOkGoogleVoiceSearch)) {
+      // TODO(amistry): Load the hotword shared module.
+      hotwordId = "";
+    }
+#endif
+    if (!hotwordId.empty()) {
+      prefs_->SetString(hotwordId + ".external_update_url",
+                        extension_urls::GetWebstoreUpdateUrl().spec());
+    }
   }
 #endif
 
   UpdateBookmarksExperimentState(
       profile_->GetPrefs(),
       g_browser_process->local_state(),
       IsUserSignedin(profile_),
       BOOKMARKS_EXPERIMENT_ENABLED_FROM_SYNC_UNKNOWN);
   std::string ext_id;
   if (GetBookmarksExperimentExtensionID(profile_->GetPrefs(), &ext_id) &&
       !ext_id.empty()) {
     prefs_->SetString(ext_id + ".external_update_url",
                       extension_urls::GetWebstoreUpdateUrl().spec());
   }
 
   LoadFinished();
 }
 
 }  // namespace extensions