Add gesture target fuzzing to views

ui/views/widget/root_view.cc

Index: ui/views/widget/root_view.cc
diff --git a/ui/views/widget/root_view.cc b/ui/views/widget/root_view.cc
index 2e799a8f2324b16b68e29a426cbc8beb5646d2c9..ac6c38c77a1ae6c7d911bf23cd7d0ceb4c75d16d 100644
--- a/ui/views/widget/root_view.cc
+++ b/ui/views/widget/root_view.cc
@@ -496,10 +496,16 @@ ui::GestureStatus RootView::OnGestureEvent(const GestureEvent& event) {
     return ui::GESTURE_STATUS_UNKNOWN;
   }
 
+  gfx::Rect touch_rect(event.details().bounding_box());
+  gfx::Point touch_rect_location(touch_rect.x(), touch_rect.y());
+  ConvertPointToScreen(this, &touch_rect_location);
+  touch_rect.set_origin(touch_rect_location);
+  View *v = GetEventHandlerForRect(touch_rect);
+
   // Walk up the tree until we find a view that wants the gesture event.
-  for (gesture_handler_ = GetEventHandlerForPoint(e.location());
-      gesture_handler_ && (gesture_handler_ != this);
-      gesture_handler_ = gesture_handler_->parent()) {
+  for (gesture_handler_ = v ? v : GetEventHandlerForPoint(e.location());

[sky, 2012/08/02 15:52:08]

Seems wierd to fallback to GetEventHandlerForPoint. Can't we make
GetEventHandlerForRect always return a non-NULL?

[tdanderson, 2012/08/02 18:11:37]

The fallback is the intended behavior since GetEventHandlerForRect only
considers candidates with the >= 70% overlap. If there are none, then we try to
dispatch to the center point of the touch region (switching tabs would fall
under this case).

How would you feel about the following change (suggested by sadrul to me in
person last week)? Rename GetEventHandlerForRect to
GetEventHandlerForRectInternal and make this private. Then add a
GetEventHandlerForRect that takes in a rect and a point |p|. It calls
GetEventHandlerForRectInternal and if this returns NULL, we return
GetEventHandlerForPoint(p) instead? This will have the same behavior but
guarantees a non-NULL return value for GetEventHandlerForRect.

+       gesture_handler_ && (gesture_handler_ != this);
+       gesture_handler_ = gesture_handler_->parent()) {
     if (!gesture_handler_->enabled()) {
       // Disabled views eat events but are treated as not handled.
       return ui::GESTURE_STATUS_UNKNOWN;