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

chrome/browser/automation/ui_controls_gtk.cc

Index: chrome/browser/automation/ui_controls_gtk.cc
diff --git a/chrome/browser/automation/ui_controls_gtk.cc b/chrome/browser/automation/ui_controls_gtk.cc
index 6c7c5f715703c2a3bb275e205022d5ba2b67370c..db52ea26b83cffb7f6d5dd506200fd133bc636a3 100644
--- a/chrome/browser/automation/ui_controls_gtk.cc
+++ b/chrome/browser/automation/ui_controls_gtk.cc
@@ -41,7 +41,16 @@ class EventWaiter : public MessageLoopForUI::Observer {
   virtual ~EventWaiter() {
     MessageLoopForUI::current()->RemoveObserver(this);
   }
+#if defined(TOUCH_UI)
+  // MessageLoop::Observer implementation:
+  virtual base::EventStatus WillProcessEvent(const base::NativeEvent& event) {
+    NOTIMPLEMENTED();
+    return base::EVENT_CONTINUE;
+  }
 
+  virtual void DidProcessEvent(const base::NativeEvent& event) {
+  }
+#else
   // MessageLoop::Observer implementation:
   virtual void WillProcessEvent(GdkEvent* event) {
     if ((event->type == type_) && (--count_ == 0)) {
@@ -59,6 +68,7 @@ class EventWaiter : public MessageLoopForUI::Observer {
   virtual void DidProcessEvent(GdkEvent* event) {
     // No-op.
   }
+#endif
 
  private:
   // We pass ownership of task_ to MessageLoop when the current event is