Reland: Fix slop region boundary handling.

ui/events/event.h

 // 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.
 
 #ifndef UI_EVENTS_EVENT_H_
 #define UI_EVENTS_EVENT_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
@@ skipping 230 matching lines @@
 class EVENTS_EXPORT LocatedEvent : public Event {
  public:
   virtual ~LocatedEvent();
 
   float x() const { return location_.x(); }
   float y() const { return location_.y(); }
   void set_location(const gfx::PointF& location) { location_ = location; }
   // TODO(tdresser): Always return floating point location. See
   // crbug.com/337824.
   gfx::Point location() const { return gfx::ToFlooredPoint(location_); }
-  gfx::PointF location_f() const { return location_; }
+  const gfx::PointF& location_f() const { return location_; }
   void set_root_location(const gfx::PointF& root_location) {
     root_location_ = root_location;
   }
   gfx::Point root_location() const {
     return gfx::ToFlooredPoint(root_location_);
   }
+  const gfx::PointF& root_location_f() const {
+    return root_location_;
+  }
 
   // Transform the locations using |inverted_root_transform|.
   // This is applied to both |location_| and |root_location_|.
   virtual void UpdateForRootTransform(
       const gfx::Transform& inverted_root_transform);
 
   template <class T> void ConvertLocationToTarget(T* source, T* target) {
     if (!target || target == source)
       return;
     // TODO(tdresser): Rewrite ConvertPointToTarget to use PointF. See
@@ skipping 402 matching lines @@
   // The set of indices of ones in the binary representation of
   // touch_ids_bitfield_ is the set of touch_ids associate with this gesture.
   // This value is stored as a bitfield because the number of touch ids varies,
   // but we currently don't need more than 32 touches at a time.
   const unsigned int touch_ids_bitfield_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_H_