Cleanup SurfaceVisibility code.

gpu/command_buffer/client/context_support.h

Index: gpu/command_buffer/client/context_support.h
diff --git a/gpu/command_buffer/client/context_support.h b/gpu/command_buffer/client/context_support.h
index d6461e16f9ce2c9361b4d81ec8676edb52eb1f00..2715c8452927de37c1e1d01f00c7bb1b5ef673fa 100644
--- a/gpu/command_buffer/client/context_support.h
+++ b/gpu/command_buffer/client/context_support.h
@@ -31,10 +31,6 @@ class ContextSupport {
   // passed the glEndQueryEXT() point.
   virtual void SignalQuery(uint32 query, const base::Closure& callback) = 0;
 
-  // For onscreen contexts, indicates that the surface visibility has changed.
-  // Clients aren't expected to draw to an invisible surface.
-  virtual void SetSurfaceVisible(bool visible) = 0;
-
   // Indicates whether the context should aggressively free allocated resources.
   // If set to true, the context will purge all temporary resources when
   // flushed.