Refactor gpu::Buffer to allow different types of backing

mojo/services/gles2/command_buffer_impl.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 "mojo/services/gles2/command_buffer_impl.h"
 
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 
 #include "gpu/command_buffer/common/constants.h"
@@ skipping 100 matching lines @@
 
   command_buffer_->SetPutOffsetChangeCallback(base::Bind(
       &gpu::GpuScheduler::PutChanged, base::Unretained(scheduler_.get())));
   command_buffer_->SetGetBufferChangeCallback(base::Bind(
       &gpu::GpuScheduler::SetGetBuffer, base::Unretained(scheduler_.get())));
   command_buffer_->SetParseErrorCallback(
       base::Bind(&CommandBufferImpl::OnParseError, base::Unretained(this)));
 
   // TODO(piman): other callbacks
 
+  const size_t kSize = sizeof(gpu::CommandBufferSharedState);
   scoped_ptr<base::SharedMemory> shared_state_shm(
       new base::SharedMemory(shared_state, false));
-  if (!command_buffer_->SetSharedStateBuffer(shared_state_shm.Pass()))
+  if (!shared_state_shm->Map(kSize))
     return false;
 
+  command_buffer_->SetSharedStateBuffer(
+      gpu::MakeBackingFromSharedMemory(shared_state_shm.Pass(), kSize));
   return true;
 }
 
 void CommandBufferImpl::SetGetBuffer(int32_t buffer) {
   command_buffer_->SetGetBuffer(buffer);
 }
 
 void CommandBufferImpl::Flush(int32_t put_offset) {
   command_buffer_->Flush(put_offset);
 }
 
 void CommandBufferImpl::MakeProgress(int32_t last_get_offset) {
   // TODO(piman): handle out-of-order.
   AllocationScope scope;
   sync_client_->DidMakeProgress(command_buffer_->GetState());
 }
 
 void CommandBufferImpl::RegisterTransferBuffer(int32_t id,
                                                const ShmHandle& transfer_buffer,
                                                uint32_t size) {
   // Take ownership of the memory and map it into this process.
   // This validates the size.
   scoped_ptr<base::SharedMemory> shared_memory(
       new base::SharedMemory(transfer_buffer, false));
   if (!shared_memory->Map(size)) {
     DVLOG(0) << "Failed to map shared memory.";
     return;
   }
 
-  command_buffer_->RegisterTransferBuffer(id, shared_memory.Pass(), size);
+  command_buffer_->RegisterTransferBuffer(
+      id, gpu::MakeBackingFromSharedMemory(shared_memory.Pass(), size));
 }
 
 void CommandBufferImpl::DestroyTransferBuffer(int32_t id) {
   command_buffer_->DestroyTransferBuffer(id);
 }
 
 void CommandBufferImpl::Echo(const Callback<void()>& callback) {
   callback.Run();
 }
 
 void CommandBufferImpl::RequestAnimationFrames() {
   timer_.Start(FROM_HERE,
                base::TimeDelta::FromMilliseconds(16),
                this,
                &CommandBufferImpl::DrawAnimationFrame);
 }
 
 void CommandBufferImpl::CancelAnimationFrames() { timer_.Stop(); }
 
 void CommandBufferImpl::OnParseError() {
   gpu::CommandBuffer::State state = command_buffer_->GetState();
   client_->LostContext(state.context_lost_reason);
 }
 
 void CommandBufferImpl::DrawAnimationFrame() { client_->DrawAnimationFrame(); }
 
 }  // namespace services
 }  // namespace mojo