Revert 97050 - Add PluginMessageLoopProxy and use it for Host plugin UI thread.

remoting/host/chromoting_host_unittest.cc

Index: remoting/host/chromoting_host_unittest.cc
===================================================================
--- remoting/host/chromoting_host_unittest.cc	(revision 97052)
+++ remoting/host/chromoting_host_unittest.cc	(working copy)
@@ -78,7 +78,7 @@
     ON_CALL(context_, network_message_loop())
         .WillByDefault(Return(message_loop_proxy_.get()));
     ON_CALL(context_, ui_message_loop())
-        .WillByDefault(Return(message_loop_proxy_.get()));
+        .WillByDefault(Return(&message_loop_));
     EXPECT_CALL(context_, main_message_loop())
         .Times(AnyNumber());
     EXPECT_CALL(context_, encode_message_loop())
@@ -88,6 +88,12 @@
     EXPECT_CALL(context_, ui_message_loop())
         .Times(AnyNumber());
 
+    context_.SetUITaskPostFunction(base::Bind(
+        static_cast<void(MessageLoop::*)(
+            const tracked_objects::Location&,
+            const base::Closure&)>(&MessageLoop::PostTask),
+        base::Unretained(&message_loop_)));
+
     Capturer* capturer = new CapturerFake();
     event_executor_ = new MockEventExecutor();
     curtain_ = new MockCurtain();