Update PPB_VideoDecoder documentation.

ppapi/cpp/video_decoder.h

 // 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.
 
 #ifndef PPAPI_CPP_VIDEO_DECODER_H_
 #define PPAPI_CPP_VIDEO_DECODER_H_
 
 #include "ppapi/c/pp_codecs.h"
 #include "ppapi/c/pp_size.h"
 #include "ppapi/cpp/completion_callback.h"
@@ skipping 63 matching lines @@
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
   /// Returns PP_ERROR_NOTSUPPORTED if video decoding is not available, or the
   /// requested profile is not supported. In this case, the client may call
   /// Initialize() again with different parameters to find a good configuration.
   int32_t Initialize(const Graphics3D& graphics3d_context,
                      PP_VideoProfile profile,
                      bool allow_software_fallback,
                      const CompletionCallback& callback);
 
   /// Decodes a bitstream buffer. Copies |size| bytes of data from the plugin's
-  /// |buffer|. The plugin should maintain the buffer and not call Decode()
-  /// again until the decoder signals completion by returning PP_OK or by
-  /// running |callback|.
+  /// |buffer|. The plugin should wait until the decoder signals completion by
+  /// returning PP_OK or by running |callback| before calling Decode() again.
   ///
   /// In general, each bitstream buffer should contain a demuxed bitstream frame
   /// for the selected video codec. For example, H264 decoders expect to receive
   /// one AnnexB NAL unit, including the 4 byte start code prefix, while VP8
   /// decoders expect to receive a bitstream frame without the IVF frame header.
   ///
   /// If the call to Decode() eventually results in a picture, the |decode_id|
   /// parameter is copied into the returned picture. The plugin can use this to
   /// associate decoded pictures with Decode() calls (e.g. to assign timestamps
   /// or frame numbers to pictures.) This value is opaque to the API so the
@@ skipping 62 matching lines @@
   /// @param[in] callback A <code>CompletionCallback</code> to be called on
   /// completion.
   ///
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
   int32_t Reset(const CompletionCallback& callback);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_VIDEO_DECODER_H_