Consolidate message observer API for win and aura (and touch).

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 5f17610172a13cf2b547aa56799c862860c93959..d0d32f6ed7083dfd592c1b87e17855de766b8170 100644
--- a/base/message_pump_win.h
+++ b/base/message_pump_win.h
@@ -13,6 +13,7 @@
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "base/message_pump.h"
+#include "base/message_pump_observer.h"
 #include "base/observer_list.h"
 #include "base/time.h"
 #include "base/win/scoped_handle.h"
@@ -24,23 +25,6 @@ namespace base {
 // controlling the lifetime of the message pump.
 class BASE_EXPORT MessagePumpWin : public MessagePump {
  public:
-  // An Observer is an object that receives global notifications from the
-  // UI MessageLoop.
-  //
-  // NOTE: An Observer implementation should be extremely fast!
-  //
-  class BASE_EXPORT Observer {
-   public:
-    virtual ~Observer() {}
-
-    // This method is called before processing a message.
-    // The message may be undefined in which case msg.message is 0
-    virtual void WillProcessMessage(const MSG& msg) = 0;
-
-    // This method is called when control returns from processing a UI message.
-    // The message may be undefined in which case msg.message is 0
-    virtual void DidProcessMessage(const MSG& msg) = 0;
-  };
 
   // Dispatcher is used during a nested invocation of Run to dispatch events.
   // If Run is invoked with a non-NULL Dispatcher, MessageLoop does not
@@ -62,11 +46,11 @@ class BASE_EXPORT MessagePumpWin : public MessagePump {
   virtual ~MessagePumpWin() {}
 
   // Add an Observer, which will start receiving notifications immediately.
-  void AddObserver(Observer* observer);
+  void AddObserver(MessagePumpObserver* observer);
 
   // Remove an Observer.  It is safe to call this method while an Observer is
   // receiving a notification callback.
-  void RemoveObserver(Observer* observer);
+  void RemoveObserver(MessagePumpObserver* observer);
 
   // Give a chance to code processing additional messages to notify the
   // message loop observers that another message has been processed.
@@ -95,7 +79,7 @@ class BASE_EXPORT MessagePumpWin : public MessagePump {
   virtual void DoRunLoop() = 0;
   int GetCurrentDelay() const;
 
-  ObserverList<Observer> observers_;
+  ObserverList<MessagePumpObserver> observers_;
 
   // The time at which delayed work should run.
   TimeTicks delayed_work_time_;