Added a unique command buffer ID for command buffers.

ppapi/proxy/ppapi_command_buffer_proxy.cc

Index: ppapi/proxy/ppapi_command_buffer_proxy.cc
diff --git a/ppapi/proxy/ppapi_command_buffer_proxy.cc b/ppapi/proxy/ppapi_command_buffer_proxy.cc
index 7a42524bff2fe2827ffbce153f9d62f1a011b108..c430c784d167347e85536a6ca85d8b373fab2c3d 100644
--- a/ppapi/proxy/ppapi_command_buffer_proxy.cc
+++ b/ppapi/proxy/ppapi_command_buffer_proxy.cc
@@ -17,8 +17,10 @@ PpapiCommandBufferProxy::PpapiCommandBufferProxy(
     const ppapi::HostResource& resource,
     PluginDispatcher* dispatcher,
     const gpu::Capabilities& capabilities,
-    const SerializedHandle& shared_state)
-    : capabilities_(capabilities),
+    const SerializedHandle& shared_state,
+    uint64_t command_buffer_id)
+    : command_buffer_id_(command_buffer_id),
+      capabilities_(capabilities),
       resource_(resource),
       dispatcher_(dispatcher) {
   shared_state_shm_.reset(
@@ -177,6 +179,14 @@ bool PpapiCommandBufferProxy::IsGpuChannelLost() {
   return false;
 }
 
+gpu::CommandBufferNamespace PpapiCommandBufferProxy::GetNamespaceID() const {
+  return gpu::CommandBufferNamespace::GPU_IO;
+}
+
+uint64_t PpapiCommandBufferProxy::GetCommandBufferID() const {
+  return command_buffer_id_;
+}
+
 uint32 PpapiCommandBufferProxy::InsertSyncPoint() {
   uint32 sync_point = 0;
   if (last_state_.error == gpu::error::kNoError) {