Add enable_vp9 option to host config.

remoting/host/host_config.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 REMOTING_HOST_HOST_CONFIG_H_
 #define REMOTING_HOST_HOST_CONFIG_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 22 matching lines @@
 // Normally a random UUID.
 extern const char kHostIdConfigPath[];
 // Readable host name.
 extern const char kHostNameConfigPath[];
 // Hash of the host secret used for authentication.
 extern const char kHostSecretHashConfigPath[];
 // Private keys used for host authentication.
 extern const char kPrivateKeyConfigPath[];
 // Whether consent is given for usage stats reporting.
 extern const char kUsageStatsConsentConfigPath[];
+// Whether to offer VP9 encoding to clients.
+extern const char kEnableVp9ConfigPath[];
 
 // HostConfig interace provides read-only access to host configuration.
 class HostConfig {
  public:
   HostConfig() {}
   virtual ~HostConfig() {}
 
   virtual bool GetString(const std::string& path,
                          std::string* out_value) const = 0;
   virtual bool GetBoolean(const std::string& path, bool* out_value) const = 0;
@@ skipping 20 matching lines @@
 
   // Saves changes.
   virtual bool Save() = 0;
 
   DISALLOW_COPY_AND_ASSIGN(MutableHostConfig);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_HOST_CONFIG_H_