Turned UiStrings into a singleton so that the continue window does not depend on ChromotingHost.

remoting/host/host_mock_objects.h

Index: remoting/host/host_mock_objects.h
diff --git a/remoting/host/host_mock_objects.h b/remoting/host/host_mock_objects.h
index e8dd33a2d4f970c53c038d859d7afebc1b0e2b9b..f1b462c3b593fc01a21e931d702893ddbbe6cfd3 100644
--- a/remoting/host/host_mock_objects.h
+++ b/remoting/host/host_mock_objects.h
@@ -15,7 +15,6 @@
 #include "remoting/host/event_executor.h"
 #include "remoting/host/host_status_observer.h"
 #include "remoting/host/local_input_monitor.h"
-#include "remoting/host/ui_strings.h"
 #include "remoting/proto/control.pb.h"
 #include "testing/gmock/include/gmock/gmock.h"
 
@@ -26,8 +25,7 @@ class MockDisconnectWindow : public DisconnectWindow {
   MockDisconnectWindow();
   virtual ~MockDisconnectWindow();
 
-  MOCK_METHOD3(Show, bool(const UiStrings& ui_strings,
-                          const base::Closure& disconnect_callback,
+  MOCK_METHOD2(Show, bool(const base::Closure& disconnect_callback,
                           const std::string& username));
   MOCK_METHOD0(Hide, void());
 };
@@ -47,8 +45,7 @@ class MockContinueWindow : public ContinueWindow {
   MockContinueWindow();
   virtual ~MockContinueWindow();
 
-  MOCK_METHOD2(Show, void(
-      remoting::ChromotingHost* host,
+  MOCK_METHOD1(Show, void(
       const remoting::ContinueWindow::ContinueSessionCallback& callback));
   MOCK_METHOD0(Hide, void());
 };