Use AutoThread in ChromotingHostContext & NPAPI plugin.

remoting/host/host_mock_objects.cc

Index: remoting/host/host_mock_objects.cc
diff --git a/remoting/host/host_mock_objects.cc b/remoting/host/host_mock_objects.cc
index 32db03ebf6638e63ac8da42a2685d54599aa857c..0c441c55c70b99518af61e5528f4c09448b0841b 100644
--- a/remoting/host/host_mock_objects.cc
+++ b/remoting/host/host_mock_objects.cc
@@ -73,13 +73,6 @@ scoped_ptr<LocalInputMonitor> LocalInputMonitor::Create() {
   return scoped_ptr<LocalInputMonitor>(new MockLocalInputMonitor());
 }
 
-MockChromotingHostContext::MockChromotingHostContext()
-    : ChromotingHostContext(new AutoThreadTaskRunner(
-          base::MessageLoopProxy::current())) {
-}
-
-MockChromotingHostContext::~MockChromotingHostContext() {}
-
 MockClientSessionEventHandler::MockClientSessionEventHandler() {}
 
 MockClientSessionEventHandler::~MockClientSessionEventHandler() {}