Add ability for EventGenerator to generate Scroll events asynchronously

ui/aura/root_window.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/root_window.h"
 
 #include <vector>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 760 matching lines @@
 
 bool RootWindow::OnHostScrollEvent(ui::ScrollEvent* event) {
   DispatchHeldMouseMove();
 
   TransformEventForDeviceScaleFactor(event);
   SetLastMouseLocation(this, event->location());
   synthesize_mouse_move_ = false;
 
   Window* target = mouse_pressed_handler_ ?
       mouse_pressed_handler_ : client::GetCaptureWindow(this);
+
   if (!target)
     target = GetEventHandlerForPoint(event->location());
 
-  if (target && target->delegate()) {
-    int flags = event->flags();
-    gfx::Point location_in_window = event->location();
-    Window::ConvertPointToTarget(this, target, &location_in_window);
-    if (IsNonClientLocation(target, location_in_window))
-      flags |= ui::EF_IS_NON_CLIENT;
-    event->set_flags(flags);
-    event->ConvertLocationToTarget(static_cast<Window*>(this), target);
-    ProcessEvent(target, event);
-    return event->handled();
-  }
-  return false;
+  if (!target)
+    target = this;
+
+  int flags = event->flags();
+  gfx::Point location_in_window = event->location();
+  Window::ConvertPointToTarget(this, target, &location_in_window);
+  if (IsNonClientLocation(target, location_in_window))
+    flags |= ui::EF_IS_NON_CLIENT;
+  event->set_flags(flags);
+  event->ConvertLocationToTarget(static_cast<Window*>(this), target);
+  ProcessEvent(target, event);
+  return event->handled();
 }
 
 bool RootWindow::OnHostTouchEvent(ui::TouchEvent* event) {
   DispatchHeldMouseMove();
   switch (event->type()) {
     case ui::ET_TOUCH_PRESSED:
       touch_ids_down_ |= (1 << event->touch_id());
       Env::GetInstance()->set_touch_down(touch_ids_down_ != 0);
       break;
 
@@ skipping 200 matching lines @@
   ui::MouseEvent event(ui::ET_MOUSE_MOVED,
                        orig_mouse_location,
                        orig_mouse_location,
                        ui::EF_IS_SYNTHESIZED);
   event.set_system_location(Env::GetInstance()->last_mouse_location());
   OnHostMouseEvent(&event);
 #endif
 }
 
 }  // namespace aura