Reapply "Add a switch to enable composited scrolling for frames and enable it on Android"

content/browser/android/content_startup_flags.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 "content/browser/android/content_startup_flags.h"
 
 #include "base/string_number_conversions.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "cc/switches.h"
@@ skipping 33 matching lines @@
     content::RenderProcessHost::SetMaxRendererProcessCount(
         max_render_process_count);
   }
 
   parsed_command_line->AppendSwitch(switches::kForceCompositingMode);
   parsed_command_line->AppendSwitch(switches::kAllowWebUICompositing);
   parsed_command_line->AppendSwitch(switches::kEnableThreadedCompositing);
   parsed_command_line->AppendSwitch(
       switches::kEnableCompositingForFixedPosition);
   parsed_command_line->AppendSwitch(switches::kEnableAcceleratedOverflowScroll);
+  parsed_command_line->AppendSwitch(
+      switches::kEnableAcceleratedScrollableFrames);
+  parsed_command_line->AppendSwitch(
+      switches::kEnableCompositedScrollingForFrames);
 
   parsed_command_line->AppendSwitch(switches::kEnableGestureTapHighlight);
   parsed_command_line->AppendSwitch(switches::kEnableCssTransformPinch);
 
   // Run the GPU service as a thread in the browser instead of as a
   // standalone process.
   parsed_command_line->AppendSwitch(switches::kInProcessGPU);
 
   // Always use fixed layout and viewport tag.
   parsed_command_line->AppendSwitch(switches::kEnableFixedLayout);
   parsed_command_line->AppendSwitch(switches::kEnableViewport);
 
   // FIXME(aelias): Commented out due to flaky tests.
 //  parsed_command_line->AppendSwitch(
 //      cc::switches::kEnableCompositorFrameMessage);
 }
 
 }  // namespace content