Add gesture target fuzzing to views

ui/views/widget/root_view.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/views/widget/root_view.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/message_loop.h"
@@ skipping 478 matching lines @@
         status = scroll_gesture_handler_->ProcessGestureEvent(gesture_event);
         if (status == ui::GESTURE_STATUS_CONSUMED)
           return status;
       }
       scroll_gesture_handler_ = NULL;
     }
 
     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;
     }
 
     // See if this view wants to handle the Gesture.
     GestureEvent gesture_event(e, this, gesture_handler_);
     status = gesture_handler_->ProcessGestureEvent(gesture_event);
 
     // The view could have removed itself from the tree when handling
@@ skipping 86 matching lines @@
 }
 
 void RootView::SetMouseLocationAndFlags(const MouseEvent& event) {
   last_mouse_event_flags_ = event.flags();
   last_mouse_event_x_ = event.x();
   last_mouse_event_y_ = event.y();
 }
 
 }  // namespace internal
 }  // namespace views