Fix IsBaseOf in output_traits.h.

ppapi/cpp/dev/audio_input_dev.h

 // 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.
 
 #ifndef PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_
 #define PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_
 
 #include <vector>
 
 #include "ppapi/c/dev/ppb_audio_input_dev.h"
@@ skipping 41 matching lines @@
   /// @return A mutable reference to the PPB_AudioConfig struct.
   AudioConfig& config() { return config_; }
 
   /// Getter function for returning the internal <code>PPB_AudioConfig</code>
   /// struct.
   ///
   /// @return A const reference to the internal <code>PPB_AudioConfig</code>
   /// struct.
   const AudioConfig& config() const { return config_; }
 
-  // TODO(yzshen, brettw): If we forward declare DeviceRef_Dev (as opposed to
-  // including its .h file), it still compiles. However, it is not recognized as
-  // a derived class of Resource and does the wrong thing!
-  // This is due to the limitation of IsBaseOf in ppapi/cpp/output_traits.h. We
-  // need to figure out a way to overcome this problem.
   int32_t EnumerateDevices(
       const CompletionCallbackWithOutput<std::vector<DeviceRef_Dev> >&
           callback);
 
   /// If |device_ref| is null (i.e., is_null() returns true), the default device
   /// will be used.
   /// In order to maintain backward compatibility, this method doesn't have
   /// input parameters config, audio_input_callback and user_data. Instead, it
   /// uses those values stored when the 4-parameter constructor was called.
   ///
@@ skipping 17 matching lines @@
   AudioConfig config_;
 
   // Used to store the arguments of Open() for the v0.2 interface.
   PPB_AudioInput_Callback audio_input_callback_;
   void* user_data_;
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_DEV_AUDIO_INPUT_DEV_H_