Command to mark surface inactive, so gpu process can release resources.

content/renderer/gpu/command_buffer_proxy.h

Index: content/renderer/gpu/command_buffer_proxy.h
diff --git a/content/renderer/gpu/command_buffer_proxy.h b/content/renderer/gpu/command_buffer_proxy.h
index efb89fe9bd08dbdbf6f55b033a08f015afa823c5..a65f882f34de11ccaeb5088f72e48729c2c3cbc6 100644
--- a/content/renderer/gpu/command_buffer_proxy.h
+++ b/content/renderer/gpu/command_buffer_proxy.h
@@ -70,6 +70,9 @@ class CommandBufferProxy : public gpu::CommandBuffer,
   // the task whether the echo succeeds or not.
   bool Echo(const base::Closure& callback);
 
+  // Sends an IPC message with the new state of surface visibility
+  bool SetSurfaceVisible(bool visible);
+
   // Reparent a command buffer. TODO(apatrick): going forward, the notion of
   // the parent / child relationship between command buffers is going away in
   // favor of the notion of surfaces that can be drawn to in one command buffer