Add PP_VideoFrame, PPB_VideoReader, and PPB_VideoWriter APIs to Pepper.

ppapi/api/pp_video_frame.idl

+/* Copyright (c) 2013 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 struct used to hold a video frame.
+ */
+
+/**
+ * The <code>PP_Video_Frame</code> struct represents a video frame.
+ */
+[assert_size(16)]
+struct PP_VideoFrame {
+  /**
+   * A timestamp placing the frame in a video stream.
+   */
+  PP_TimeTicks timestamp;
+
+  /**
+   * An image data resource to hold the video frame.
+   */
+  PP_Resource image_data;
+
+  /**
+   * Ensure that this struct is 16-bytes wide by padding the end.  In some
+   * compilers, PP_TimeTicks is 8-byte aligned, so those compilers align this
+   * struct on 8-byte boundaries as well and pad it to 8 bytes even without this
+   * padding attribute.  This padding makes its size consistent across
+   * compilers.
+   */
+  int32_t padding;
+};
+