events: Update scroll and touch handlers to not return EventResult.

ash/wm/window_modality_controller_unittest.cc

Index: ash/wm/window_modality_controller_unittest.cc
diff --git a/ash/wm/window_modality_controller_unittest.cc b/ash/wm/window_modality_controller_unittest.cc
index 94a647c9cff4a20d080884d429a986d53cf4ffca..65927afa9c1920d8795e104e6848b7fb823d10ea 100644
--- a/ash/wm/window_modality_controller_unittest.cc
+++ b/ash/wm/window_modality_controller_unittest.cc
@@ -298,9 +298,9 @@ class TouchTrackerWindowDelegate : public aura::test::TestWindowDelegate {
 
  private:
   // Overridden from aura::test::TestWindowDelegate.
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE {
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE {
     received_touch_ = true;
-    return aura::test::TestWindowDelegate::OnTouchEvent(event);
+    aura::test::TestWindowDelegate::OnTouchEvent(event);
   }
 
   bool received_touch_;