Partial raster for GPU

cc/raster/one_copy_raster_buffer_provider.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 "cc/raster/one_copy_raster_buffer_provider.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <limits>
@@ skipping 135 matching lines @@
   }
 
   return resource_provider_->best_texture_format();
 }
 
 bool OneCopyRasterBufferProvider::IsResourceSwizzleRequired(
     bool must_support_alpha) const {
   return ResourceFormatRequiresSwizzle(GetResourceFormat(must_support_alpha));
 }
 
-bool OneCopyRasterBufferProvider::IsPartialRasterSupported() const {
-  return true;
+bool OneCopyRasterBufferProvider::CanPartialRasterIntoProvidedResource() const {
+  // While OneCopyRasterBufferProvider has an internal partial raster
+  // implementation, it cannot directly partial raster into the externally
+  // owned resource provided in AcquireBufferForRaster.
+  return false;
 }
 
 void OneCopyRasterBufferProvider::Shutdown() {
   staging_pool_.Shutdown();
   pending_raster_buffers_.clear();
 }
 
 void OneCopyRasterBufferProvider::PlaybackAndCopyOnWorkerThread(
     const Resource* resource,
     ResourceProvider::ScopedWriteLockGL* resource_lock,
@@ skipping 206 matching lines @@
   gl->OrderingBarrierCHROMIUM();
 
   // Generate sync token after the barrier for cross context synchronization.
   gpu::SyncToken resource_sync_token;
   gl->GenUnverifiedSyncTokenCHROMIUM(fence_sync, resource_sync_token.GetData());
   resource_lock->set_sync_token(resource_sync_token);
   resource_lock->set_synchronized(!async_worker_context_enabled_);
 }
 
 }  // namespace cc