Revert of Delete the enable/disable layer squashing flags and settings.

content/browser/renderer_host/render_view_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.
 
 #include "content/browser/renderer_host/render_view_host_impl.h"
 
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 362 matching lines @@
   prefs.flash_stage3d_enabled =
       GpuProcessHost::gpu_enabled() &&
       !command_line.HasSwitch(switches::kDisableFlashStage3d);
   prefs.flash_stage3d_baseline_enabled =
       GpuProcessHost::gpu_enabled() &&
       !command_line.HasSwitch(switches::kDisableFlashStage3d);
 
   prefs.allow_file_access_from_file_urls =
       command_line.HasSwitch(switches::kAllowFileAccessFromFiles);
 
+  prefs.layer_squashing_enabled = true;
+  if (command_line.HasSwitch(switches::kEnableLayerSquashing))
+      prefs.layer_squashing_enabled = true;
+  if (command_line.HasSwitch(switches::kDisableLayerSquashing))
+      prefs.layer_squashing_enabled = false;
+
   prefs.accelerated_2d_canvas_enabled =
       GpuProcessHost::gpu_enabled() &&
       !command_line.HasSwitch(switches::kDisableAccelerated2dCanvas);
   prefs.antialiased_2d_canvas_disabled =
       command_line.HasSwitch(switches::kDisable2dCanvasAntialiasing);
   prefs.antialiased_clips_2d_canvas_enabled =
       command_line.HasSwitch(switches::kEnable2dCanvasClipAntialiasing);
   prefs.accelerated_2d_canvas_msaa_sample_count =
       atoi(command_line.GetSwitchValueASCII(
       switches::kAcceleratedCanvas2dMSAASampleCount).c_str());
@@ skipping 1085 matching lines @@
   FrameTree* frame_tree = delegate_->GetFrameTree();
 
   frame_tree->ResetForMainFrameSwap();
 }
 
 void RenderViewHostImpl::SelectWordAroundCaret() {
   Send(new ViewMsg_SelectWordAroundCaret(GetRoutingID()));
 }
 
 }  // namespace content