Add optimization for CHROMIUM_subscribe_uniform extension.

content/browser/gpu/gpu_process_host_ui_shim.cc

Index: content/browser/gpu/gpu_process_host_ui_shim.cc
diff --git a/content/browser/gpu/gpu_process_host_ui_shim.cc b/content/browser/gpu/gpu_process_host_ui_shim.cc
index 2293e745892609f8391e4d01e628cbc4bfc83abb..3b9c8968c6c168032986796bf7923165b63b61f4 100644
--- a/content/browser/gpu/gpu_process_host_ui_shim.cc
+++ b/content/browser/gpu/gpu_process_host_ui_shim.cc
@@ -230,6 +230,8 @@ bool GpuProcessHostUIShim::OnControlMessageReceived(
                         OnVideoMemoryUsageStatsReceived);
     IPC_MESSAGE_HANDLER(GpuHostMsg_ResourcesRelinquished,
                         OnResourcesRelinquished)
+    IPC_MESSAGE_HANDLER(GpuHostMsg_AddSubscription, OnAddSubscription);
+    IPC_MESSAGE_HANDLER(GpuHostMsg_RemoveSubscription, OnRemoveSubscription);
 
     IPC_MESSAGE_UNHANDLED_ERROR()
   IPC_END_MESSAGE_MAP()
@@ -306,4 +308,20 @@ void GpuProcessHostUIShim::OnResourcesRelinquished() {
   }
 }
 
+void GpuProcessHostUIShim::OnAddSubscription(
+    int32 process_id, unsigned int target) {
+  RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
+  if (rph) {
+    rph->OnAddSubscription(target);
+  }
+}
+
+void GpuProcessHostUIShim::OnRemoveSubscription(
+    int32 process_id, unsigned int target) {
+  RenderProcessHost* rph = RenderProcessHost::FromID(process_id);
+  if (rph) {
+    rph->OnRemoveSubscription(target);
+  }
+}
+
 }  // namespace content