Add UMA stats for GPU feature disable checkbox.

chrome/common/pref_names.cc

 // Copyright (c) 2012 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/common/pref_names.h"
 
 #include "base/basictypes.h"
 #include "chrome/common/pref_font_webkit_names.h"
 
 namespace prefs {
@@ skipping 2166 matching lines @@
 // one when uninstalling background apps.
 const char kUserRemovedLoginItem[] = "background_mode.user_removed_login_item";
 
 // Set to true if background mode is enabled on this browser.
 const char kBackgroundModeEnabled[] = "background_mode.enabled";
 
 // Set to true if hardware acceleration mode is enabled on this browser.
 const char kHardwareAccelerationModeEnabled[] =
   "hardware_acceleration_mode.enabled";
 
+// Hardware acceleration mode from previous browser launch.
+const char kHardwareAccelerationModePrevious[] =
+  "hardware_acceleration_mode_previous";
+
 // List of protocol handlers.
 const char kRegisteredProtocolHandlers[] =
   "custom_handlers.registered_protocol_handlers";
 
 // List of protocol handlers the user has requested not to be asked about again.
 const char kIgnoredProtocolHandlers[] =
   "custom_handlers.ignored_protocol_handlers";
 
 // Whether user-specified handlers for protocols and content types can be
 // specified.
@@ skipping 179 matching lines @@
 // the time of the last ping.
 extern const char kAppListLaunchCount[] = "app_list.launch_count";
 extern const char kLastAppListLaunchPing[] = "app_list.last_launch_ping";
 
 // The number of times the an app was launched from the app launcher since last
 // ping and the time of the last ping.
 extern const char kAppListAppLaunchCount[] = "app_list.app_launch_count";
 extern const char kLastAppListAppLaunchPing[] = "app_list.last_app_launch_ping";
 
 }  // namespace prefs