Add subscribeUniform extension pipeline

gpu/command_buffer/service/context_state.h

Index: gpu/command_buffer/service/context_state.h
diff --git a/gpu/command_buffer/service/context_state.h b/gpu/command_buffer/service/context_state.h
index 7488f5786c84e2df845aa9a40577582aee9540a4..b4e812c295c6becb5a29988c61d0631dc8b9123c 100644
--- a/gpu/command_buffer/service/context_state.h
+++ b/gpu/command_buffer/service/context_state.h
@@ -13,6 +13,7 @@
 #include "gpu/command_buffer/service/gl_utils.h"
 #include "gpu/command_buffer/service/query_manager.h"
 #include "gpu/command_buffer/service/texture_manager.h"
+#include "gpu/command_buffer/service/valuebuffer_manager.h"
 #include "gpu/command_buffer/service/vertex_attrib_manager.h"
 #include "gpu/command_buffer/service/vertex_array_manager.h"
 #include "gpu/gpu_export.h"
@@ -200,6 +201,9 @@ struct GPU_EXPORT ContextState {
   scoped_refptr<Renderbuffer> bound_renderbuffer;
   bool bound_renderbuffer_valid;
 
+  // The currently bound valuebuffer
+  scoped_refptr<Valuebuffer> bound_valuebuffer;
+
   // A map of of target -> Query for current queries
   typedef std::map<GLuint, scoped_refptr<QueryManager::Query> > QueryMap;
   QueryMap current_queries;