Disable partial swaps for webview guest renderer until we can figure out how to do that properly.

content/renderer/gpu/render_widget_compositor.cc

 // Copyright (c) 2013 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/renderer/gpu/render_widget_compositor.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/logging.h"
@@ skipping 150 matching lines @@
 
   if (cmd->HasSwitch(cc::switches::kTopControlsHideThreshold)) {
       std::string top_threshold_str =
           cmd->GetSwitchValueASCII(cc::switches::kTopControlsHideThreshold);
       double hide_threshold;
       if (base::StringToDouble(top_threshold_str, &hide_threshold) &&
           hide_threshold >= 0.f && hide_threshold <= 1.f)
         settings.topControlsHideThreshold = hide_threshold;
   }
 
-  settings.partialSwapEnabled =
+  settings.partialSwapEnabled = widget->AllowPartialSwap() &&
       cmd->HasSwitch(cc::switches::kEnablePartialSwap);
   settings.backgroundColorInsteadOfCheckerboard =
       cmd->HasSwitch(cc::switches::kBackgroundColorInsteadOfCheckerboard);
   settings.showOverdrawInTracing =
       cmd->HasSwitch(cc::switches::kTraceOverdraw);
 
   settings.initialDebugState.showFPSCounter =
       cmd->HasSwitch(switches::kShowFPSCounter);
   settings.initialDebugState.showPaintRects =
       cmd->HasSwitch(switches::kShowPaintRects);
@@ skipping 312 matching lines @@
   return RenderThreadImpl::current()->OffscreenContextProviderForMainThread();
 }
 
 scoped_refptr<cc::ContextProvider>
 RenderWidgetCompositor::OffscreenContextProviderForCompositorThread() {
   return RenderThreadImpl::current()->
       OffscreenContextProviderForCompositorThread();
 }
 
 }  // namespace content