Do not call into EventTargeter methods from ViewTargeter

ui/views/view_targeter_delegate.h

 // Copyright 2014 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_VIEWS_VIEW_TARGETER_DELEGATE_H_
 #define UI_VIEWS_VIEW_TARGETER_DELEGATE_H_
 
 #include "base/macros.h"
 #include "ui/views/views_export.h"
 
 namespace gfx {
 class Rect;
 }
 
 namespace views {
 class View;
 
-// Defines the default behaviour for hit-testing a rectangular region against
-// the bounds of a View. Subclasses of View wishing to define custom
-// hit-testing behaviour can extend this class.
+// Defines the default behaviour for hit-testing and event-targeting against a
+// View using a rectangular region representing an event's location. Views
+// wishing to define custom hit-testing or event-targeting behaviour do so by
+// extending ViewTargeterDelegate and then installing a ViewTargeter on
+// themselves.
 class VIEWS_EXPORT ViewTargeterDelegate {
  public:
   ViewTargeterDelegate() {}
   virtual ~ViewTargeterDelegate() {}
 
   // Returns true if the bounds of |target| intersects |rect|, where |rect|
   // is in the local coodinate space of |target|. Overrides of this method by
   // a View subclass should enforce DCHECK_EQ(this, target).
   virtual bool DoesIntersectRect(const View* target,
                                  const gfx::Rect& rect) const;
 
   // If point-based targeting should be used, return the deepest visible
   // descendant of |root| that contains the center point of |rect|.
   // If rect-based targeting (i.e., fuzzing) should be used, return the
   // closest visible descendant of |root| having at least kRectTargetOverlap of
   // its area covered by |rect|. If no such descendant exists, return the
   // deepest visible descendant of |root| that contains the center point of
   // |rect|. See http://goo.gl/3Jp2BD for more information about rect-based
   // targeting.
   virtual View* TargetForRect(View* root, const gfx::Rect& rect);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ViewTargeterDelegate);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_TARGETER_DELEGATE_H_