Add a flag to disable partial raster in renderer

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 1120 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 (IsPersistentGpuMemoryBufferEnabled())
-    command_line->AppendSwitch(switches::kEnablePersistentGpuMemoryBuffer);
+  if (IsPartialRasterEnabled())
+    command_line->AppendSwitch(switches::kEnablePartialRaster);
 
   if (IsForceGpuRasterizationEnabled())
     command_line->AppendSwitch(switches::kForceGpuRasterization);
 
-  gfx::BufferUsage buffer_usage = IsPersistentGpuMemoryBufferEnabled()
+  // Persistent buffers may come at a performance hit (not all platform specific
+  // buffers support it), so only enable them if partial raster is enabled and
+  // we are actually going to use them.
+  gfx::BufferUsage buffer_usage = IsPartialRasterEnabled()
                                       ? gfx::BufferUsage::PERSISTENT_MAP
                                       : gfx::BufferUsage::MAP;
   std::vector<unsigned> image_targets(
       static_cast<size_t>(gfx::BufferFormat::LAST) + 1, GL_TEXTURE_2D);
   for (size_t format = 0;
        format < static_cast<size_t>(gfx::BufferFormat::LAST) + 1; format++) {
     image_targets[format] =
         BrowserGpuMemoryBufferManager::GetImageTextureTarget(
             static_cast<gfx::BufferFormat>(format), buffer_usage);
   }
@@ skipping 1374 matching lines @@
 void RenderProcessHostImpl::GetAudioOutputControllers(
     const GetAudioOutputControllersCallback& callback) const {
   audio_renderer_host()->GetOutputControllers(callback);
 }
 
 BluetoothDispatcherHost* RenderProcessHostImpl::GetBluetoothDispatcherHost() {
   return bluetooth_dispatcher_host_.get();
 }
 
 }  // namespace content