Added a unique command buffer ID for command buffers.

ppapi/proxy/ppapi_command_buffer_proxy.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 "ppapi/proxy/ppapi_command_buffer_proxy.h"
 
 #include "base/numerics/safe_conversions.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/host_resource.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 
 namespace ppapi {
 namespace proxy {
 
+// TODO(dyen): to support fences on Ppapi, we need to plumb the command buffer
+// id that the ppapi command buffer forwards to.
 PpapiCommandBufferProxy::PpapiCommandBufferProxy(
     const ppapi::HostResource& resource,
     PluginDispatcher* dispatcher,
     const gpu::Capabilities& capabilities,
     const SerializedHandle& shared_state)
-    : capabilities_(capabilities),
+    : CommandBuffer(gpu::kCommandBufferNamespace_Invalid, 0),
+      capabilities_(capabilities),
       resource_(resource),
       dispatcher_(dispatcher) {
   shared_state_shm_.reset(
       new base::SharedMemory(shared_state.shmem(), false));
   shared_state_shm_->Map(shared_state.size());
   InstanceData* data = dispatcher->GetInstanceData(resource.instance());
   flush_info_ = &data->flush_info_;
 }
 
 PpapiCommandBufferProxy::~PpapiCommandBufferProxy() {
@@ skipping 262 matching lines @@
   // cached last_state_ with out-of-date data.
   message->set_unblock(true);
   Send(message);
 
   flush_info_->flush_pending = false;
   flush_info_->resource.SetHostResource(0, 0);
 }
 
 }  // namespace proxy
 }  // namespace ppapi