gpu: Compositor management of GpuMemoryBuffer instances.

cc/resources/zero_copy_raster_worker_pool.cc

 // Copyright 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 "cc/resources/zero_copy_raster_worker_pool.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_argument.h"
 #include "base/strings/stringprintf.h"
 #include "cc/debug/traced_value.h"
 #include "cc/resources/raster_buffer.h"
 #include "cc/resources/resource.h"
 #include "third_party/skia/include/utils/SkNullCanvas.h"
+#include "ui/gfx/gpu_memory_buffer.h"
 
 namespace cc {
 namespace {
 
 class RasterBufferImpl : public RasterBuffer {
  public:
   RasterBufferImpl(ResourceProvider* resource_provider,
                    const Resource* resource)
       : lock_(resource_provider, resource->id()),
         resource_(resource),
         buffer_(NULL) {}
 
   // Overridden from RasterBuffer:
   virtual skia::RefPtr<SkCanvas> AcquireSkCanvas() override {
-    buffer_ = lock_.gpu_memory_buffer();
-    if (!buffer_)
+    gfx::GpuMemoryBuffer* gpu_memory_buffer = lock_.gpu_memory_buffer();
+    if (!gpu_memory_buffer)
       return skia::AdoptRef(SkCreateNullCanvas());
 
+    buffer_ = gpu_memory_buffer->Map();
     RasterWorkerPool::AcquireBitmapForBuffer(&bitmap_,
                                              buffer_,
                                              resource_->format(),
                                              resource_->size(),
-                                             lock_.stride());
+                                             gpu_memory_buffer->GetStride());
     return skia::AdoptRef(new SkCanvas(bitmap_));
   }
   virtual void ReleaseSkCanvas(const skia::RefPtr<SkCanvas>& canvas) override {
-    if (!buffer_)
+    gfx::GpuMemoryBuffer* gpu_memory_buffer = lock_.gpu_memory_buffer();
+    if (!gpu_memory_buffer)
       return;
 
     RasterWorkerPool::ReleaseBitmapForBuffer(
         &bitmap_, buffer_, resource_->format());
+    gpu_memory_buffer->Unmap();
   }
 
  private:
   ResourceProvider::ScopedWriteLockGpuMemoryBuffer lock_;
   const Resource* resource_;
   void* buffer_;
   SkBitmap bitmap_;
 
   DISALLOW_COPY_AND_ASSIGN(RasterBufferImpl);
 };
@@ skipping 156 matching lines @@
       new base::debug::TracedValue();
 
   state->BeginArray("tasks_pending");
   for (TaskSet task_set = 0; task_set < kNumberOfTaskSets; ++task_set)
     state->AppendBoolean(raster_pending_[task_set]);
   state->EndArray();
   return state;
 }
 
 }  // namespace cc