Preliminary compositor disabling patch.

content/browser/compositor/gpu_surfaceless_browser_compositor_output_surface.cc

 // Copyright 2014 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/compositor/gpu_surfaceless_browser_compositor_output_surface.h"
 
 #include "cc/output/compositor_frame.h"
 #include "content/browser/compositor/buffer_queue.h"
 #include "content/browser/compositor/reflector_impl.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
@@ skipping 29 matching lines @@
 }
 
 GpuSurfacelessBrowserCompositorOutputSurface::
     ~GpuSurfacelessBrowserCompositorOutputSurface() {
 }
 
 void GpuSurfacelessBrowserCompositorOutputSurface::SwapBuffers(
     cc::CompositorFrame* frame) {
   DCHECK(output_surface_);
 
-  GLuint texture = output_surface_->current_texture_id();
-  output_surface_->SwapBuffers(frame->gl_frame_data->sub_buffer_rect);
+  GLuint texture;
+  if (!frame->gl_frame_data->sub_buffer_rect.IsEmpty()) {
+    texture = output_surface_->current_texture_id();
+    output_surface_->SwapBuffers(frame->gl_frame_data->sub_buffer_rect);
+  } else {
+    texture = output_surface_->last_texture_id();
+  }
   const gfx::Size& size = frame->gl_frame_data->size;
   context_provider_->ContextGL()->ScheduleOverlayPlaneCHROMIUM(
       0,
       GL_OVERLAY_TRANSFORM_NONE_CHROMIUM,
       texture,
       0,
       0,
       size.width(),
       size.height(),
       0,
@@ skipping 16 matching lines @@
 
 void GpuSurfacelessBrowserCompositorOutputSurface::Reshape(
     const gfx::Size& size,
     float scale_factor) {
   GpuBrowserCompositorOutputSurface::Reshape(size, scale_factor);
   DCHECK(output_surface_);
   output_surface_->Reshape(SurfaceSize(), scale_factor);
 }
 
 }  // namespace content