Add optimization for CHROMIUM_subscribe_uniform extension.

content/common/gpu/gpu_channel.h

Index: content/common/gpu/gpu_channel.h
diff --git a/content/common/gpu/gpu_channel.h b/content/common/gpu/gpu_channel.h
index 6b707289cc55df3a924f66619667f332ceeb7966..56ac41f57203446744bb392ad17cb6b12a9cff2d 100644
--- a/content/common/gpu/gpu_channel.h
+++ b/content/common/gpu/gpu_channel.h
@@ -37,6 +37,7 @@ class PreemptionFlag;
 union ValueState;
 class ValueStateMap;
 namespace gles2 {
+class SubscriptionRefSet;
 }
 }
 
@@ -59,6 +60,7 @@ class GpuChannel : public IPC::Listener, public IPC::Sender {
              GpuWatchdog* watchdog,
              gfx::GLShareGroup* share_group,
              gpu::gles2::MailboxManager* mailbox_manager,
+             gpu::gles2::SubscriptionRefSet* subscription_ref_set,
              int client_id,
              bool software,
              bool allow_future_sync_points);
@@ -219,6 +221,8 @@ class GpuChannel : public IPC::Listener, public IPC::Sender {
 
   scoped_refptr<gpu::gles2::MailboxManager> mailbox_manager_;
 
+  scoped_refptr<gpu::gles2::SubscriptionRefSet> subscription_ref_set_;
+
   scoped_refptr<gpu::ValueStateMap> pending_valuebuffer_state_;
 
   typedef IDMap<GpuCommandBufferStub, IDMapOwnPointer> StubMap;