Add glue between the client and engine for Blimp

blimp/common/proto/input.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.
 //
 // Message definitions for the input subprotocol.
 //
 // The InputMessage protobuf generally carries web input events.  Currently we
 // just serialize the blink::WebInputEvent POD struct.
 
 syntax = "proto2";
@@ skipping 76 matching lines @@
     Type_GestureFlingStart = 4;
     Type_GestureFlingCancel = 5;
     Type_GestureTap = 6;
     Type_GesturePinchBegin = 7;
     Type_GesturePinchEnd = 8;
     Type_GesturePinchUpdate = 9;
   }
 
   optional Type type = 1;
 
+  // An ID that corresponds to RenderWidgetMessage.
+  optional uint32 render_widget_id = 12;
+
   // The time this input event happened relative to when the client device was
   // started.
   optional double timestamp_seconds = 2;
 
   // Input event specific messages follow.
   // Only one of these fields may be set per InputMessage.
   optional GestureScrollBegin gesture_scroll_begin = 3;
   optional GestureScrollEnd gesture_scroll_end = 4;
   optional GestureScrollUpdate gesture_scroll_update = 5;
   optional GestureFlingStart gesture_fling_start = 6;
   optional GestureFlingCancel gesture_fling_cancel = 7;
   optional GestureTap gesture_tap = 8;
   optional GesturePinchBegin gesture_pinch_begin = 9;
   optional GesturePinchEnd gesture_pinch_end = 10;
   optional GesturePinchUpdate gesture_pinch_update = 11;
 }