cc: Remove all blimp code from cc.

cc/proto/layer_selection_bound.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 "point.proto";
-
-option optimize_for = LITE_RUNTIME;
-
-package cc.proto;
-
-message LayerSelectionBound {
-  enum SelectionBoundType {
-    UNKNOWN = 0;
-    LEFT = 1;
-    RIGHT = 2;
-    CENTER = 3;
-    EMPTY = 4;
-  }
-
-  optional SelectionBoundType type = 1;
-  optional Point edge_top = 2;
-  optional Point edge_bottom = 3;
-  optional int32 layer_id = 4;
-}
-
-message LayerSelection {
-  optional LayerSelectionBound start = 1;
-  optional LayerSelectionBound end = 2;
-  optional bool is_editable = 3;
-  optional bool is_empty_text_form_control = 4;
-}