[Tizen] Murphy resource policy daemon integration

Integrate WebMediaPlayer with Murphy resource policy daemon, so that the
policy framework can handle the media playback based on the role of audio
stream.

This branch includes common classes and Chromium side changes that are
needed for integrating WebMediaPlayer with the Murphy resource policy
daemon. 

The WebMediaPlayer executes in the Renderer -- as such, it does not have direct
native access. So, the WebMediaPlayer requests browser process to create murphy
resource for the given player id and define the media role. The media player
control operations(play/pause) are communicated with the resource daemon using
BrowserMediaPlayerManager object in the browser process through proxy. Also, the
control operations received from the resource daemon are converted to IPCs and
then send back to the media player in the render process.

BUG=XWALK-1668
why "virtual" is needed? is it planned to be inherited?