compositor: Enable partial raster by default.

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright 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 1261 matching lines @@
     command_line->AppendSwitch(switches::kEnableGpuRasterization);
 
   int msaa_sample_count = GpuRasterizationMSAASampleCount();
   if (msaa_sample_count >= 0) {
     command_line->AppendSwitchASCII(switches::kGpuRasterizationMSAASampleCount,
                                     base::IntToString(msaa_sample_count));
   }
 
   if (IsZeroCopyUploadEnabled())
     command_line->AppendSwitch(switches::kEnableZeroCopy);
-  if (IsPartialRasterEnabled())
-    command_line->AppendSwitch(switches::kEnablePartialRaster);
+  if (!IsPartialRasterEnabled())
+    command_line->AppendSwitch(switches::kDisablePartialRaster);
 
   if (IsForceGpuRasterizationEnabled())
     command_line->AppendSwitch(switches::kForceGpuRasterization);
 
   if (IsGpuMemoryBufferCompositorResourcesEnabled()) {
     command_line->AppendSwitch(
         switches::kEnableGpuMemoryBufferCompositorResources);
   }
 
   // Persistent buffers may come at a performance hit (not all platform specific
@@ skipping 1501 matching lines @@
 
     // Skip widgets in other processes.
     if (rvh->GetProcess()->GetID() != GetID())
       continue;
 
     rvh->OnWebkitPreferencesChanged();
   }
 }
 
 }  // namespace content