Enable accelerated overflow scrolling for high dpi.

content/browser/renderer_host/render_process_host_impl.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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 921 matching lines @@
 #if defined(OS_MACOSX)
     // Allow this to be set when invoking the browser and relayed along.
     switches::kEnableSandboxLogging,
 #endif
     switches::kEnableSoftwareCompositingGLAdapter,
     switches::kEnableStatsTable,
     switches::kEnableThreadedCompositing,
     switches::kEnableCompositingForFixedPosition,
     switches::kEnableHighDpiCompositingForFixedPosition,
     switches::kDisableCompositingForFixedPosition,
+    switches::kEnableAcceleratedOverflowScroll,
     switches::kEnableCompositingForTransition,
     switches::kDisableCompositingForTransition,
     switches::kDisableThreadedCompositing,
     switches::kDisableTouchAdjustment,
     switches::kDefaultTileWidth,
     switches::kDefaultTileHeight,
     switches::kMaxUntiledLayerWidth,
     switches::kMaxUntiledLayerHeight,
     switches::kEnableViewport,
     switches::kEnableOpusPlayback,
@@ skipping 824 matching lines @@
     // Skip widgets in other processes.
     if (widgets[i]->GetProcess()->GetID() != GetID())
       continue;
 
     RenderViewHost* rvh = RenderViewHost::From(widgets[i]);
     rvh->UpdateWebkitPreferences(rvh->GetWebkitPreferences());
   }
 }
 
 }  // namespace content