Add VP9 decode support to the remoting client.

remoting/protocol/session_config.h

Index: remoting/protocol/session_config.h
diff --git a/remoting/protocol/session_config.h b/remoting/protocol/session_config.h
index ac5f0c193574556c2bdb0476451a84e5a9a650c2..b3fa90a51178b5ffe78a2507002523223af184ef 100644
--- a/remoting/protocol/session_config.h
+++ b/remoting/protocol/session_config.h
@@ -32,6 +32,7 @@ struct ChannelConfig {
     CODEC_VERBATIM,
     CODEC_ZIP,
     CODEC_VP8,
+    CODEC_VP9,
     CODEC_OPUS,
     CODEC_SPEEX,
   };
@@ -157,8 +158,10 @@ class CandidateSessionConfig {
       const SessionConfig& config);
   static scoped_ptr<CandidateSessionConfig> CreateDefault();
 
-  // Helper method that modifies |config| to disable audio support.
+  // Modifies |config| to disable specific features.
   static void DisableAudioChannel(CandidateSessionConfig* config);
+  static void DisableVideoCodec(CandidateSessionConfig* config,
+                                ChannelConfig::Codec codec);
 
  private:
   CandidateSessionConfig();