cc: Remove all blimp code from cc.

cc/proto/layer_tree_host.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";
-
-import "display_item.proto";
-import "layer.proto";
-import "layer_tree.proto";
-
-package cc.proto;
-
-option optimize_for = LITE_RUNTIME;
-
-message SkPictureData {
-  optional SkPictureID id = 1;
-  optional bytes payload = 2; /* SkData */
-}
-
-message SkPictures {
-  repeated SkPictureData pictures = 1;
-}
-
-message LayerTreeHost {
-  // Not all members of LayerTreeHost are serialized, as they are not helpful
-  // for remote usage. See implementation of
-  // cc::LayerTreeHost::ToProtobufForCommit for details.
-  optional LayerTree layer_tree = 36;
-  optional LayerUpdate layer_updates = 28;
-  optional SkPictures pictures = 38;
-}