Make sure that base::MessagePumpForUI from different modules are isolated from each other and add p…

base/message_pump_win.h

Index: base/message_pump_win.h
diff --git a/base/message_pump_win.h b/base/message_pump_win.h
index f5a00f3015ecc4a2e61f57e07a44311eb4fdb8ec..7514bae253b221728f97e1b0710303d849f3569e 100644
--- a/base/message_pump_win.h
+++ b/base/message_pump_win.h
@@ -154,6 +154,12 @@ class BASE_EXPORT MessagePumpForUI : public MessagePumpWin {
   bool ProcessMessageHelper(const MSG& msg);
   bool ProcessPumpReplacementMessage();
 
+  // Atom representing the message-only window class.
+  ATOM atom_;
+
+  // Instance of the module containing the window procedure.
+  HMODULE instance_;
+
   // A hidden message-only window.
   HWND message_hwnd_;
 };