AW hardware draw mega patch

cc/resources/resource_provider.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.
 
 #include "cc/resources/resource_provider.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/debug/alias.h"
@@ skipping 1346 matching lines @@
 uint8_t* ResourceProvider::MapImage(ResourceId id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ResourceMap::iterator it = resources_.find(id);
   CHECK(it != resources_.end());
   Resource* resource = &it->second;
 
   DCHECK(ReadLockFenceHasPassed(resource));
   DCHECK(!resource->external);
   DCHECK(!resource->exported);
   DCHECK(!resource->pixels);
-  DCHECK(resource->image_id);
+
+  if (!resource->image_id)
+    return NULL;
 
   WebGraphicsContext3D* context3d = output_surface_->context3d();
   DCHECK(context3d);
   return static_cast<uint8_t*>(
       context3d->mapImageCHROMIUM(resource->image_id, GL_READ_WRITE));
 }
 
 void ResourceProvider::UnmapImage(ResourceId id) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ResourceMap::iterator it = resources_.find(id);
@@ skipping 43 matching lines @@
 
   WebGraphicsContext3D* context3d = output_surface_->context3d();
   DCHECK(context3d);
   int stride = 0;
   context3d->getImageParameterivCHROMIUM(
       resource->image_id, GL_IMAGE_ROWBYTES_CHROMIUM, &stride);
   return stride;
 }
 
 }  // namespace cc