cc: Remove all blimp code from cc.

cc/proto/compositor_message.proto

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-
-import "client_state_update.proto";
-import "layer_tree_host.proto";
-
-package cc.proto;
-
-// A top level message for serialized state used by the compositor remote
-// channels.
-// TODO(khushalsagar): Remove CompositorMessage and stop using
-// RemoteProtoChannel to plumb these to/from the browser. See crbug.com/648442
-message CompositorMessage {
-  // Engine -> Client
-  // Frame Update.
-  optional LayerTreeHost layer_tree_host = 3;
-
-  // Client -> Engine
-  // Sent from the client to the engine when a frame update was processed
-  // on the client.
-  optional bool frame_ack = 4;
-
-  // Client -> Engine
-  // Reports any changes made to the main thread state on the compositor thread
-  // on the client.
-  optional ClientStateUpdate client_state_update = 5;
-
-  // Engine -> Client
-  // Acknowledges the application of the client state update to the associated
-  // state on the engine.
-  // If the application of the update resulted in any additional changes to the
-  // state on the engine, the ack will always be bundled with the resulting
-  // frame update.
-  optional bool client_state_update_ack = 6;
-}