Make VideoCapture_Dev backward compatible.

ppapi/api/dev/ppb_video_capture_dev.idl

 /* Copyright (c) 2012 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.
  */
 
 /**
  * This file defines the <code>PPB_VideoCapture_Dev</code> interface.
  */
 label Chrome {
   M14 = 0.1,
-  M18 = 0.2
+  M19 = 0.2
 };
 
 /**
  * Video capture interface. It goes hand-in-hand with PPP_VideoCapture_Dev.
  *
  * Theory of operation:
  * 1- Create a VideoCapture resource using Create.
  * 2- Find available video capture devices using EnumerateDevices.
  * 3- Open a video capture device. In addition to a device reference (0 can be
  * used to indicate the default device), you pass in the requested info
@@ skipping 125 matching lines @@
   /**
    * Closes the video capture device, and stops capturing if necessary. It is
    * not valid to call |Open()| again after a call to this method.
    * If a video capture resource is destroyed while a device is still open, then
    * it will be implicitly closed, so you are not required to call this method.
    */
   [version=0.2]
   void Close(
       [in] PP_Resource video_capture);
 };