Removing GL context rate limiting feature and related wrappers

cc/trees/proxy.h

Index: cc/trees/proxy.h
diff --git a/cc/trees/proxy.h b/cc/trees/proxy.h
index 57efe3f4c1c608e3093c2014dc650cff0a3e440b..598ee0eff05a5b8f5cb23a01c62d34b7e89209bd 100644
--- a/cc/trees/proxy.h
+++ b/cc/trees/proxy.h
@@ -93,10 +93,6 @@ class CC_EXPORT Proxy {
   virtual void Start() = 0;
   virtual void Stop() = 0;   // Must be called before deleting the proxy.
 
-  // Forces 3D commands on all contexts to wait for all previous SwapBuffers
-  // to finish before executing in the GPU process.
-  virtual void ForceSerializeOnSwapBuffers() = 0;
-
   virtual bool SupportsImplScrolling() const = 0;
 
   virtual void SetChildrenNeedBeginFrames(bool children_need_begin_frames) = 0;