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

chrome/browser/notifications/balloon_collection_impl.h

Index: chrome/browser/notifications/balloon_collection_impl.h
diff --git a/chrome/browser/notifications/balloon_collection_impl.h b/chrome/browser/notifications/balloon_collection_impl.h
index 2b4af231835a11bd97b5bf666fd3bf5dfaad4100..b47c2c06cbfd715ed542217c7359d582970a6e64 100644
--- a/chrome/browser/notifications/balloon_collection_impl.h
+++ b/chrome/browser/notifications/balloon_collection_impl.h
@@ -54,12 +54,19 @@ class BalloonCollectionImpl : public BalloonCollection
 
   // MessageLoopForUI::Observer interface.
 #if defined(OS_WIN)
-  virtual void WillProcessMessage(const MSG& event) {}
-  virtual void DidProcessMessage(const MSG& event);
-#endif
-#if defined(TOOLKIT_USES_GTK)
-  virtual void WillProcessEvent(GdkEvent* event) {}
-  virtual void DidProcessEvent(GdkEvent* event);
+  virtual base::EventStatus WillProcessEvent(const MSG& event) OVERRIDE {
+    return base::EVENT_CONTINUE;
+  }
+  virtual void DidProcessEvent(const MSG& event) OVERRIDE;
+#elif defined(TOUCH_UI) || defined(USE_AURA)
+  virtual base::EventStatus WillProcessEvent(
+      const base::NativeEvent& event) OVERRIDE {
+    return base::EVENT_CONTINUE;
+  }
+  virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE;
+#elif defined(TOOLKIT_USES_GTK)
+  virtual void WillProcessEvent(GdkEvent* event) OVERRIDE {}
+  virtual void DidProcessEvent(GdkEvent* event) OVERRIDE;
 #endif
 
  protected: