Bug 242142

RemoteRenderingBackend::stopListeningForIPC() is calling StreamServerConnection::stopReceivingMessages() after it dispatch a code block code which clear its m_remoteResourceCache. But this can allow incoming messages to be dispatched to RemoteRenderingBackend including the message RemoteRenderingBackend::ReleaseRemoteResource. If this message is received after clearing m_remoteResourceCache, GPUProcess will simulate-crash with the message "Resource is being released before being cached." To fix this, we need to call StreamServerConnection::stopReceivingMessages() before clearing the resource cache. Once this call is returned, no incoming stream connection messages can be dispatched to RemoteRenderingBackend. RemoteRenderingBackend::m_workQueue will remove RemoteRenderingBackend::m_streamConnection as its connection. And RemoteRenderingBackend::m_streamConnection will remove the RemoteRenderingBackend as its message receiver. So StreamConnectionWorkQueue::processStreams() won't process the messages of RemoteRenderingBackend::m_streamConnection. After we call StreamServerConnection::stopReceivingMessages(), we can dispatch the code block which clears m_remoteResourceCache. This code has be executed on the stream connection WorkQueue. The WorkQueue should be still running after calling StreamServerConnection::stopReceivingMessages(). It will be executed by StreamConnectionWorkQueue::processStreams() when processing m_functions. After dispatching the code block which clears m_remoteResourceCache, we need to call StreamConnectionWorkQueue::stopAndWaitForCompletion() to ensure the code block is executed and the WorkQueue has been stopped.