Add a way to cancel a started message.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40020 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/drawing/remote/RemoteMessage.cpp

@@ -56,6 +56,14 @@ RemoteMessage::NextMessage(uint16& code)
 }
 
 
+void
+RemoteMessage::Cancel()
+{
+	fAvailable += fWriteIndex;
+	fWriteIndex = 0;
+}
+
+
 #ifndef CLIENT_COMPILE
 void
 RemoteMessage::AddBitmap(const ServerBitmap& bitmap, bool minimal)

src/servers/app/drawing/remote/RemoteMessage.h

@@ -133,6 +133,7 @@ public:
 
 		void					Start(uint16 code);
 		status_t				Flush();
+		void					Cancel();
 
 		status_t				NextMessage(uint16& code);
 		uint16					Code() { return fCode; }