Moving SwitchOutputDevice out of OutputDevice interface, eliminating OutputDevice

media/audio/audio_parameters.h

Index: media/audio/audio_parameters.h
diff --git a/media/audio/audio_parameters.h b/media/audio/audio_parameters.h
index 2735d79af927889eef786b9acd907140230fd3ac..d7d730b91497b1a6bd145961c5ce7b6e0ec6f2c1 100644
--- a/media/audio/audio_parameters.h
+++ b/media/audio/audio_parameters.h
@@ -177,6 +177,9 @@ class MEDIA_EXPORT AudioParameters {
   AudioParameters(const AudioParameters&);
   AudioParameters& operator=(const AudioParameters&);
 
+  // Creates reasonable dummy parameters in case no device is available.

[DaleCurtis, 2016/03/29 19:57:43]

Hmm, this meaning is a bit unclear. It seems to imply this specifically means
that when these parameters are seen they mean they are for an unavailable
device. Which doesn't seem strictly true. They only appear used in one place
too, maybe they should live there instead?

[o1ka, 2016/03/30 14:02:42]

Not quite in one place, it's actuallly freshly borrowed for here
https://codereview.chromium.org/1809093003/diff/120001/content/browser/render...
and used initially by AudioRendererHost only. We want to be consistent with it
and return the same values when the sink is no associated with a output
device(yet or at all) or output device is not available/not authorized.

+  static AudioParameters UnavailableDeviceParams();
+
  private:
   Format format_;                 // Format of the stream.
   ChannelLayout channel_layout_;  // Order of surround sound channels.