Add SetVideoMode API to avsettings

chromecast/public/avsettings.h

Index: chromecast/public/avsettings.h
diff --git a/chromecast/public/avsettings.h b/chromecast/public/avsettings.h
index be12e2183c309a8e4e343073c9374a511652cd5f..136ce15622e576c7dcb2359f0dcad632f0f07579 100644
--- a/chromecast/public/avsettings.h
+++ b/chromecast/public/avsettings.h
@@ -291,6 +291,25 @@ class AvSettings {
 
   // Gets the current HDR output type.
   virtual HdrOutputType GetHdrOutputType() = 0;
+
+  // Sets the HDMI video mode according to the given parameters:
+  //

[halliwell, 2016/10/03 21:05:28]

nit, can lose blank line

+  // |allow_4k|: if false, the resolution set will not be a 4K resolution.
+  //

[halliwell, 2016/10/03 21:05:28]

ditto

+  // |optimize_for_fps|: *Attempts* to pick a refresh rate optimal for the
+  // given content frame rate. |optimize_for_fps| is expressed as framerate
+  // * 100. I.e. 24hz -> 2400, 23.98hz -> 2398, etc.  Values <= 0 are ignored.
+  //
+  // Returns:
+  // - true if HDMI video mode change is beginning.  Caller should wait for
+  //   SCREEN_INFO_CHANGED event for mode change to complete.
+  // - false if no HDMI video mode change has begun.  This could be because
+  // HDMI is disconnected, or the current resolution is already good for the
+  // given parameters.
+  //

[halliwell, 2016/10/03 21:05:28]

nit, lose one of these blank lines.

+  //
+  // This API only applies to devices that output HDMI, otherwise return false.

[halliwell, 2016/10/03 21:05:27]

This sentence is weird.  Just "Non-HDMI devices should return false." ?

+  virtual bool SetHdmiVideoMode(bool allow_4k, int optimize_for_fps) = 0;
 };
 
 }  // namespace chromecast