Added flag in chrome://flags to enable the New Launcher UI.

ui/app_list/app_list_switches.cc

 // Copyright 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 "ui/app_list/app_list_switches.h"
 
 #include "base/command_line.h"
 
 namespace app_list {
 namespace switches {
 
 // Specifies the chrome-extension:// URL for the contents of an additional page
 // added to the app launcher.
 const char kCustomLauncherPage[] = "custom-launcher-page";
 
 // If set, the app list will not be dismissed when it loses focus. This is
 // useful when testing the app list or a custom launcher page. It can still be
 // dismissed via the other methods (like the Esc key).
 const char kDisableAppListDismissOnBlur[] = "disable-app-list-dismiss-on-blur";
 
 // If set, the app list will be enabled as if enabled from CWS.
 const char kEnableAppList[] = "enable-app-list";
 
+// If set, fullscreen app list will be enabled as if the feature flag was set.
+const char kEnableFullscreenAppList[] = "enable-fullscreen-app-list";
+
 // Enable/disable syncing of the app list independent of extensions.
 const char kEnableSyncAppList[] = "enable-sync-app-list";
 const char kDisableSyncAppList[] = "disable-sync-app-list";
 
 // Enable/disable drive search in chrome launcher.
 const char kEnableDriveSearchInChromeLauncher[] =
     "enable-drive-search-in-app-launcher";
 const char kDisableDriveSearchInChromeLauncher[] =
     "disable-drive-search-in-app-launcher";
 
 // If set, the app list will forget it has been installed on startup. Note this
 // doesn't prevent the app list from running, it just makes Chrome think the app
 // list hasn't been enabled (as in kEnableAppList) yet.
 const char kResetAppListInstallState[] = "reset-app-list-install-state";
 
 bool IsAppListSyncEnabled() {
   return !base::CommandLine::ForCurrentProcess()->HasSwitch(
       kDisableSyncAppList);
 }
 
+bool IsFullscreenAppListEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      kEnableFullscreenAppList);
+}
+
 bool IsFolderUIEnabled() {
   // Folder UI is available only when AppList sync is enabled, and should
   // not be disabled separately.
   return IsAppListSyncEnabled();
 }
 
 bool IsVoiceSearchEnabled() {
   // Speech recognition in AppList is only for ChromeOS right now.
   return true;
 }
@@ skipping 14 matching lines @@
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           kDisableDriveSearchInChromeLauncher))
     return false;
 
   return true;
 }
 
 }  // namespace switches
 }  // namespace app_list