aura: Remove event-dispatch methods from WindowTreeHostDelegate interface.

ui/aura/root_window.cc

Index: ui/aura/root_window.cc
diff --git a/ui/aura/root_window.cc b/ui/aura/root_window.cc
index 1a72b9abe645e546a9d5323672e729483dc4c2ab..6fe53b66dc73a95a5f3706e66f809c4a51c2d6bf 100644
--- a/ui/aura/root_window.cc
+++ b/ui/aura/root_window.cc
@@ -638,7 +638,9 @@ void RootWindow::DispatchPostponedGestureEvent(ui::GestureEvent* event) {
 }
 
 void RootWindow::DispatchCancelTouchEvent(ui::TouchEvent* event) {
-  OnHostTouchEvent(event);
+  DispatchDetails details = OnEventFromSource(event);
+  if (details.dispatcher_destroyed)
+    return;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -660,34 +662,6 @@ void RootWindow::OnLayerAnimationAborted(
 ////////////////////////////////////////////////////////////////////////////////
 // RootWindow, WindowTreeHostDelegate implementation:
 
-bool RootWindow::OnHostKeyEvent(ui::KeyEvent* event) {
-  DispatchDetails details = OnEventFromSource(event);
-  if (details.dispatcher_destroyed)
-    event->SetHandled();
-  return event->handled();
-}
-
-bool RootWindow::OnHostMouseEvent(ui::MouseEvent* event) {
-  DispatchDetails details = OnEventFromSource(event);
-  if (details.dispatcher_destroyed)
-    event->SetHandled();
-  return event->handled();
-}
-
-bool RootWindow::OnHostScrollEvent(ui::ScrollEvent* event) {
-  DispatchDetails details = OnEventFromSource(event);
-  if (details.dispatcher_destroyed)
-    event->SetHandled();
-  return event->handled();
-}
-
-bool RootWindow::OnHostTouchEvent(ui::TouchEvent* event) {
-  DispatchDetails details = OnEventFromSource(event);
-  if (details.dispatcher_destroyed)
-    event->SetHandled();
-  return event->handled();
-}
-
 void RootWindow::OnHostCancelMode() {
   ui::CancelModeEvent event;
   Window* focused_window = client::GetFocusClient(window())->GetFocusedWindow();