Cast audio only policy enforcement support.

extensions/browser/api/cast_channel/cast_socket.h

Index: extensions/browser/api/cast_channel/cast_socket.h
diff --git a/extensions/browser/api/cast_channel/cast_socket.h b/extensions/browser/api/cast_channel/cast_socket.h
index 2cb56a6ea538d35accf0e6dfdb705d0fa2f69bec..e9dd5c353b04cef49b4c47a9f41637e02ffb9224 100644
--- a/extensions/browser/api/cast_channel/cast_socket.h
+++ b/extensions/browser/api/cast_channel/cast_socket.h
@@ -125,7 +125,8 @@ class CastSocketImpl : public CastSocket {
                  ChannelAuthType channel_auth,
                  net::NetLog* net_log,
                  const base::TimeDelta& connect_timeout,
-                 const scoped_refptr<Logger>& logger);
+                 const scoped_refptr<Logger>& logger,
+                 long device_capabilities);
 
   // Ensures that the socket is closed.
   ~CastSocketImpl() override;
@@ -242,6 +243,11 @@ class CastSocketImpl : public CastSocket {
   void SetConnectState(proto::ConnectionState connect_state);
   void SetReadyState(ReadyState ready_state);
 
+  // Verifies whether the socket complies with cast channel policy.
+  // Audio only channel policy mandates that a device declaring a video out
+  // capability must not have a certificate with audio only policy.
+  bool VerifyChannelPolicy(const AuthResult& result);
+
   base::ThreadChecker thread_checker_;
 
   const std::string owner_extension_id_;
@@ -294,6 +300,9 @@ class CastSocketImpl : public CastSocket {
   // canceled.
   bool is_canceled_;
 
+  // Capabilities declared by the cast device.
+  long device_capabilities_;
+
   // Connection flow state machine state.
   proto::ConnectionState connect_state_;