cc: Move GpuMemoryBuffer allocation to worker threads.

cc/resources/one_copy_raster_worker_pool.cc

Index: cc/resources/one_copy_raster_worker_pool.cc
diff --git a/cc/resources/one_copy_raster_worker_pool.cc b/cc/resources/one_copy_raster_worker_pool.cc
index 5b8a5c16ea7dd47fce9aa264aef44bc80f1a33b6..ef0f19da00a40c59b620d875acdf1cc2e809fc74 100644
--- a/cc/resources/one_copy_raster_worker_pool.cc
+++ b/cc/resources/one_copy_raster_worker_pool.cc
@@ -32,14 +32,16 @@ class RasterBufferImpl : public RasterBuffer {
         lock_(new ResourceProvider::ScopedWriteLockGpuMemoryBuffer(
             resource_provider_,
             raster_resource_->id())),
-        buffer_(NULL) {}
+        gpu_memory_buffer_(nullptr),
+        buffer_(nullptr) {}
 
   virtual ~RasterBufferImpl() {
     // First unlock raster resource.
     lock_.reset();
 
     // Copy contents of raster resource to |resource_|.
-    resource_provider_->CopyResource(raster_resource_->id(), resource_->id());
+    if (gpu_memory_buffer_)
+      resource_provider_->CopyResource(raster_resource_->id(), resource_->id());
 
     // Return raster resource to pool so it can be used by another RasterBuffer
     // instance.
@@ -48,26 +50,25 @@ class RasterBufferImpl : public RasterBuffer {
 
   // Overridden from RasterBuffer:
   virtual skia::RefPtr<SkCanvas> AcquireSkCanvas() override {
-    gfx::GpuMemoryBuffer* gpu_memory_buffer = lock_->gpu_memory_buffer();
-    if (!gpu_memory_buffer)
+    gpu_memory_buffer_ = lock_->GetGpuMemoryBuffer();
+    if (!gpu_memory_buffer_)
       return skia::AdoptRef(SkCreateNullCanvas());
 
-    buffer_ = gpu_memory_buffer->Map();
+    buffer_ = gpu_memory_buffer_->Map();
     RasterWorkerPool::AcquireBitmapForBuffer(&bitmap_,
                                              buffer_,
                                              resource_->format(),
                                              resource_->size(),
-                                             gpu_memory_buffer->GetStride());
+                                             gpu_memory_buffer_->GetStride());
     return skia::AdoptRef(new SkCanvas(bitmap_));
   }
   virtual void ReleaseSkCanvas(const skia::RefPtr<SkCanvas>& canvas) override {
-    gfx::GpuMemoryBuffer* gpu_memory_buffer = lock_->gpu_memory_buffer();
-    if (!gpu_memory_buffer)
+    if (!gpu_memory_buffer_)
       return;
 
     RasterWorkerPool::ReleaseBitmapForBuffer(
         &bitmap_, buffer_, resource_->format());
-    gpu_memory_buffer->Unmap();
+    gpu_memory_buffer_->Unmap();
   }
 
  private:
@@ -76,6 +77,7 @@ class RasterBufferImpl : public RasterBuffer {
   const Resource* resource_;
   scoped_ptr<ScopedResource> raster_resource_;
   scoped_ptr<ResourceProvider::ScopedWriteLockGpuMemoryBuffer> lock_;
+  gfx::GpuMemoryBuffer* gpu_memory_buffer_;
   void* buffer_;
   SkBitmap bitmap_;