Fix stuck keys problem with Chromoting when host disconnects while keys are

remoting/protocol/input_sender.cc

Index: remoting/protocol/input_sender.cc
diff --git a/remoting/protocol/input_sender.cc b/remoting/protocol/input_sender.cc
index fb4102cb28745a3fb082ce608cec80f7c99ed170..ff45ce203cdda2d151605c90b807a371061adc3d 100644
--- a/remoting/protocol/input_sender.cc
+++ b/remoting/protocol/input_sender.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -28,6 +28,8 @@ InputSender::~InputSender() {
 }
 
 void InputSender::InjectKeyEvent(const KeyEvent* event, Task* done) {
+  DCHECK(done);
+
   EventMessage message;
   message.set_sequence_number(base::Time::Now().ToInternalValue());
   message.mutable_key_event()->CopyFrom(*event);
@@ -35,6 +37,8 @@ void InputSender::InjectKeyEvent(const KeyEvent* event, Task* done) {
 }
 
 void InputSender::InjectMouseEvent(const MouseEvent* event, Task* done) {
+  DCHECK(done);
+
   EventMessage message;
   message.set_sequence_number(base::Time::Now().ToInternalValue());
   message.mutable_mouse_event()->CopyFrom(*event);