Refactor gpu::Buffer to allow different types of backing

content/common/gpu/gpu_command_buffer_stub.cc

 // Copyright (c) 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 "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/hash.h"
 #include "base/memory/shared_memory.h"
@@ skipping 524 matching lines @@
   scheduler_->SetSchedulingChangedCallback(
       base::Bind(&GpuChannel::StubSchedulingChanged,
                  base::Unretained(channel_)));
 
   if (watchdog_) {
     scheduler_->SetCommandProcessedCallback(
         base::Bind(&GpuCommandBufferStub::OnCommandProcessed,
                    base::Unretained(this)));
   }
 
-  if (!command_buffer_->SetSharedStateBuffer(shared_state_shm.Pass())) {
-    DLOG(ERROR) << "Failed to map shared stae buffer.";
+  const size_t kSharedStateSize = sizeof(gpu::CommandBufferSharedState);
+  if (!shared_state_shm->Map(kSharedStateSize)) {
+    DLOG(ERROR) << "Failed to map shared state buffer.";
     OnInitializeFailed(reply_message);
     return;
   }
+  command_buffer_->SetSharedStateBuffer(gpu::MakeBackingFromSharedMemory(
+      shared_state_shm.Pass(), kSharedStateSize));
 
   GpuCommandBufferMsg_Initialize::WriteReplyParams(
       reply_message, true, gpu_control_->GetCapabilities());
   Send(reply_message);
 
   if (handle_.is_null() && !active_url_.is_empty()) {
     GpuChannelManager* gpu_channel_manager = channel_->gpu_channel_manager();
     gpu_channel_manager->Send(new GpuHostMsg_DidCreateOffscreenContext(
         active_url_));
   }
@@ skipping 127 matching lines @@
 
   // 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;
   }
 
-  if (command_buffer_)
-    command_buffer_->RegisterTransferBuffer(id, shared_memory.Pass(), size);
+  if (command_buffer_) {
+    command_buffer_->RegisterTransferBuffer(
+        id, gpu::MakeBackingFromSharedMemory(shared_memory.Pass(), size));
+  }
 }
 
 void GpuCommandBufferStub::OnDestroyTransferBuffer(int32 id) {
   TRACE_EVENT0("gpu", "GpuCommandBufferStub::OnDestroyTransferBuffer");
 
   if (command_buffer_)
     command_buffer_->DestroyTransferBuffer(id);
 }
 
 void GpuCommandBufferStub::OnCommandProcessed() {
@@ skipping 250 matching lines @@
   if (decoder_)
     decoder_->LoseContext(GL_UNKNOWN_CONTEXT_RESET_ARB);
   command_buffer_->SetParseError(gpu::error::kLostContext);
 }
 
 uint64 GpuCommandBufferStub::GetMemoryUsage() const {
   return GetMemoryManager()->GetClientMemoryUsage(this);
 }
 
 }  // namespace content