Attempt 2 at:

views/view.h

Index: views/view.h
diff --git a/views/view.h b/views/view.h
index c0f6f0739c19354fdec51ea5340bd207b6d4e086..a9012a56041225abe7081a88744f3167dd2956a4 100644
--- a/views/view.h
+++ b/views/view.h
@@ -178,6 +178,11 @@ class View : public AcceleratorTarget {
   void SetX(int x) { SetBounds(x, y(), width(), height()); }
   void SetY(int y) { SetBounds(x(), y, width(), height()); }
 
+  // Registers this view for mouse near events (OnMouseNear and
+  // OnMouseExitedNear). Mouse near events are sent for the extended rectangle
+  // defined by the bounds of this view + |insets|.
+  void RegisterForMouseNearEvents(const gfx::Insets& insets);
+
   // Returns the left coordinate of the View, relative to the parent View,
   // which is the value of bounds_.x().
   //
@@ -686,6 +691,18 @@ class View : public AcceleratorTarget {
   // Default implementation does nothing. Override as needed.
   virtual void OnMouseExited(const MouseEvent& event);
 
+  // Sent when the mouse enters the rectangle defined by this views bounds and
+  // the insets passed to RegisterForMouseNearEvents. This is only sent for
+  // views that have explicitly registered for near notification
+  // (RegisterForMouseNearEvents).
+  virtual void OnMouseNear(const MouseEvent& event) {}
+
+  // Sent when the mouse exits the rectangle defined by this views bounds and
+  // the insets passed to RegisterForMouseNearEvents. This is only sent for
+  // views that have explicitly registered for near notification
+  // (RegisterForMouseNearEvents).
+  virtual void OnMouseExitedNear(const MouseEvent& event) {}
+
   // Set the MouseHandler for a drag session.
   //
   // A drag session is a stream of mouse events starting
@@ -1176,11 +1193,11 @@ class View : public AcceleratorTarget {
 
   // Recursively descends through all descendant views,
   // registering/unregistering all views that want visible bounds in root
-  // view notification.
-  static void RegisterChildrenForVisibleBoundsNotification(RootView* root,
-                                                           View* view);
-  static void UnregisterChildrenForVisibleBoundsNotification(RootView* root,
-                                                             View* view);
+  // view notification and/or mouse near events.
+  static void RegisterChildrenForRootNotifications(RootView* root, View* view);
+  static void UnregisterChildrenForRootNotifications(RootView* root,
+                                                     View* view);
+
 
   // Adds/removes view to the list of descendants that are notified any time
   // this views location and possibly size are changed.
@@ -1280,6 +1297,9 @@ class View : public AcceleratorTarget {
   // right-to-left locales for this View.
   bool flip_canvas_on_paint_for_rtl_ui_;
 
+  // Insets passed to RegisterForMouseNearEvents.
+  scoped_ptr<gfx::Insets> near_insets_;
+
   // The default value for how long to wait (in ms) before showing a menu
   // button on hover. This value is used if the OS doesn't supply one.
   static const int kShowFolderDropMenuDelay;