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

content/public/common/content_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 "content/public/common/content_switches.h"
 
 namespace switches {
 
 // By default, file:// URIs cannot read other file:// URIs. This is an
 // override for developers who need the old behavior for testing.
@@ skipping 576 matching lines @@
 
 // Draws a FPS indicator
 const char kShowFPSCounter[]                = "show-fps-counter";
 
 // Enables accelerated compositing for overflow scroll. Promotes eligible
 // overflow:scroll elements to layers to enable accelerated scrolling for them.
 const char kEnableAcceleratedOverflowScroll[] =
     "enable-accelerated-overflow-scroll";
 
 // Enables accelerated compositing for scrollable frames for accelerated
-// scrolling for them.
+// scrolling for them. Requires kForceCompositingMode.
 const char kEnableAcceleratedScrollableFrames[] =
      "enable-accelerated-scrollable-frames";
 
+// Enables accelerated scrolling by the compositor for frames. Requires
+// kForceCompositingMode and kEnableAcceleratedScrollableFrames.
+const char kEnableCompositedScrollingForFrames[] =
+     "enable-composited-scrolling-for-frames";
+
 // Visibly render a border around paint rects in the web page to help debug
 // and study painting behavior.
 const char kShowPaintRects[]                = "show-paint-rects";
 
 // Map mouse input events into touch gesture events.  Useful for debugging touch
 // gestures without needing a touchscreen.
 const char kSimulateTouchScreenWithMouse[]  =
     "simulate-touch-screen-with-mouse";
 
 // Runs the renderer and plugins in the same process as the browser
@@ skipping 150 matching lines @@
     = "disable-fixed-position-creates-stacking-context";
 
 // Defer image decoding in WebKit until painting.
 const char kEnableDeferredImageDecoding[] = "enable-deferred-image-decoding";
 
 // Enables history navigation in response to horizontal overscroll.
 const char kEnableOverscrollHistoryNavigation[] =
     "enable-overscroll-history-navigation";
 
 }  // namespace switches