Add vsync notification command line switch

cc/base/switches.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 "cc/base/switches.h"
 
 #include "base/command_line.h"
 
 namespace cc {
 namespace switches {
@@ skipping 83 matching lines @@
 
 // The scale factor for low resolution tile contents.
 const char kLowResolutionContentsScaleFactor[] =
     "low-resolution-contents-scale-factor";
 
 // Causes the compositor to render to textures which are then sent to the parent
 // through the texture mailbox mechanism.
 // Requires --enable-compositor-frame-message.
 const char kCompositeToMailbox[] = "composite-to-mailbox";
 
+// Use a vsync signal from the browser to the renderer to schedule rendering.
+const char kEnableVsyncNotification[] = "enable-vsync-notification";
+
 bool IsImplSidePaintingEnabled() {
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 
   if (command_line.HasSwitch(cc::switches::kDisableImplSidePainting))
     return false;
   else if (command_line.HasSwitch(cc::switches::kEnableImplSidePainting))
     return true;
 
 #if defined(OS_ANDROID)
   return true;
 #else
   return false;
 #endif
 }
 
 }  // namespace switches
 }  // namespace cc