Pepper: Add External_OES texture target to PPB_VideoDecoder docs and example.

ppapi/api/pp_codecs.idl

 /* Copyright (c) 2014 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.
  */
 
 /**
  * Video profiles.
  */
 enum PP_VideoProfile {
   PP_VIDEOPROFILE_H264BASELINE = 0,
@@ skipping 25 matching lines @@
   uint32_t decode_id;
 
   /**
    * Texture ID in the plugin's GL context. The plugin can use this to render
    * the decoded picture.
    */
   uint32_t texture_id;
 
   /**
    * The GL texture target for the decoded picture. Possible values are:
-   *   GL_TEXTURE_2D                 (normalized texture coordinates)
-   *   GL_TEXTURE_RECTANGLE_ARB      (dimension dependent texture coordinates)
+   *   GL_TEXTURE_2D
+   *   GL_TEXTURE_RECTANGLE_ARB
+   *   GL_TEXTURE_EXTERNAL_OES
    *
    * The pixel format of the texture is GL_RGBA.
    */
   uint32_t texture_target;
 
   /**
    * Dimensions of the texture holding the decoded picture.
    */
   PP_Size texture_size;
 };