Introduce TsfEventRouter.

ui/base/win/tsf_bridge.h

Index: ui/base/win/tsf_bridge.h
diff --git a/ui/base/win/tsf_bridge.h b/ui/base/win/tsf_bridge.h
index 76023b060a3594ed0482966383994249c4331be1..0b13857380174dc0672189b865acc18afefaaadb 100644
--- a/ui/base/win/tsf_bridge.h
+++ b/ui/base/win/tsf_bridge.h
@@ -6,7 +6,10 @@
 #define UI_BASE_WIN_TSF_BRIDGE_H_
 
 #include <Windows.h>
+#include <msctf.h>
+
 #include "base/basictypes.h"
+#include "base/win/scoped_comptr.h"
 #include "ui/base/ui_export.h"
 
 namespace ui {
@@ -61,6 +64,9 @@ class UI_EXPORT TsfBridge {
   // Caller must free |client|.
   virtual void RemoveFocusedClient(TextInputClient* client) = 0;
 
+  // Obtains current thread manager.
+  virtual base::win::ScopedComPtr<ITfThreadMgr> GetThreadManager() = 0;
+
  protected:
   // Uses GetInstance() instead.
   TsfBridge();