cc: Partial tile update for one-copy raster.

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/containers/hash_tables.h"
@@ skipping 1086 matching lines @@
   if (!gpu_memory_buffer_) {
     scoped_ptr<gfx::GpuMemoryBuffer> gpu_memory_buffer =
         gpu_memory_buffer_manager_->AllocateGpuMemoryBuffer(
             size_, ToGpuMemoryBufferFormat(format_), gfx::GpuMemoryBuffer::MAP);
     gpu_memory_buffer_ = gpu_memory_buffer.release();
   }
 
   return gpu_memory_buffer_;
 }
 
+ResourceProvider::ScopedReadLockGpuMemoryBuffer::ScopedReadLockGpuMemoryBuffer(
+    ResourceProvider* resource_provider,
+    ResourceProvider::ResourceId resource_id)
+    : resource_provider_(resource_provider),
+      resource_id_(resource_id),
+      gpu_memory_buffer_(nullptr) {
+  const Resource* resource = resource_provider->LockForRead(resource_id);
+  DCHECK_EQ(RESOURCE_TYPE_GL_TEXTURE, resource->type);
+  DCHECK(resource->allocated);
+  DCHECK(resource->image_id);
+  DCHECK(resource->gpu_memory_buffer);
+  gpu_memory_buffer_ = resource->gpu_memory_buffer;
+}
+
+ResourceProvider::ScopedReadLockGpuMemoryBuffer::
+    ~ScopedReadLockGpuMemoryBuffer() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  resource_provider_->UnlockForRead(resource_id_);
+}
+
+gfx::GpuMemoryBuffer*
+ResourceProvider::ScopedReadLockGpuMemoryBuffer::GetGpuMemoryBuffer() {
+  return gpu_memory_buffer_;
+}
+
 ResourceProvider::ScopedWriteLockGr::ScopedWriteLockGr(
     ResourceProvider* resource_provider,
     ResourceProvider::ResourceId resource_id)
     : resource_provider_(resource_provider),
       resource_(resource_provider->LockForWrite(resource_id)) {
   DCHECK(thread_checker_.CalledOnValidThread());
   resource_provider_->LazyAllocate(resource_);
 }
 
 ResourceProvider::ScopedWriteLockGr::~ScopedWriteLockGr() {
@@ skipping 939 matching lines @@
 }
 
 class GrContext* ResourceProvider::GrContext(bool worker_context) const {
   ContextProvider* context_provider =
       worker_context ? output_surface_->worker_context_provider()
                      : output_surface_->context_provider();
   return context_provider ? context_provider->GrContext() : NULL;
 }
 
 }  // namespace cc