Attempt 2 at:

views/view.cc

 // Copyright (c) 2010 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 "views/view.h"
 
 #include <algorithm>
 #ifndef NDEBUG
 #include <iostream>
 #endif
@@ skipping 114 matching lines @@
 
   if (size_changed || position_changed) {
     DidChangeBounds(prev, bounds_);
 
     RootView* root = GetRootView();
     if (root)
       root->ViewBoundsChanged(this, size_changed, position_changed);
   }
 }
 
+void View::RegisterForMouseNearEvents(const gfx::Insets& insets) {
+  RootView* root = GetRootView();
+  if (insets.empty()) {
+    near_insets_.reset(NULL);
+    if (root)
+      root->UnregisterViewForNearNotification(this);
+  } else {
+    near_insets_.reset(
+        new gfx::Insets(insets.top(), insets.left(), insets.bottom(),
+                        insets.right()));
+    if (root)
+      root->RegisterViewForNearNotification(this);
+  }
+}
+
 gfx::Rect View::GetLocalBounds(bool include_border) const {
   if (include_border || !border_.get())
     return gfx::Rect(0, 0, width(), height());
 
   gfx::Insets insets;
   border_->GetInsets(&insets);
   return gfx::Rect(insets.left(), insets.top(),
                    std::max(0, width() - insets.width()),
                    std::max(0, height() - insets.height()));
 }
@@ skipping 385 matching lines @@
   child_views_.insert(child_views_.begin() + index, v);
   v->SetParent(this);
 
   for (View* p = this; p; p = p->GetParent())
     p->ViewHierarchyChangedImpl(false, true, this, v);
 
   v->PropagateAddNotifications(this, v);
   UpdateTooltip();
   RootView* root = GetRootView();
   if (root)
-    RegisterChildrenForVisibleBoundsNotification(root, v);
+    RegisterChildrenForRootNotifications(root, v);
 
   if (layout_manager_.get())
     layout_manager_->ViewAdded(this, v);
 }
 
 View* View::GetChildViewAt(int index) const {
   return index < GetChildViewCount() ? child_views_[index] : NULL;
 }
 
 int View::GetChildViewCount() const {
@@ skipping 51 matching lines @@
       View* next_focusable = a_view->next_focusable_view_;
       View* prev_focusable = a_view->previous_focusable_view_;
       if (prev_focusable)
         prev_focusable->next_focusable_view_ = next_focusable;
       if (next_focusable)
         next_focusable->previous_focusable_view_ = prev_focusable;
     }
 
     RootView* root = GetRootView();
     if (root)
-      UnregisterChildrenForVisibleBoundsNotification(root, a_view);
+      UnregisterChildrenForRootNotifications(root, a_view);
     a_view->PropagateRemoveNotifications(this);
     a_view->SetParent(NULL);
 
     if (delete_removed_view && a_view->IsParentOwned())
       delete a_view;
 
     child_views_.erase(i);
   }
 
   if (update_tool_tip)
@@ skipping 810 matching lines @@
                                  bool is_horizontal, bool is_positive) {
   return 0;
 }
 
 ThemeProvider* View::GetThemeProvider() const {
   Widget* widget = GetWidget();
   return widget ? widget->GetThemeProvider() : NULL;
 }
 
 // static
-void View::RegisterChildrenForVisibleBoundsNotification(
-    RootView* root, View* view) {
+void View::RegisterChildrenForRootNotifications(RootView* root, View* view) {
   DCHECK(root && view);
   if (view->GetNotifyWhenVisibleBoundsInRootChanges())
     root->RegisterViewForVisibleBoundsNotification(view);
+  if (view->near_insets_.get())
+    root->RegisterViewForNearNotification(view);
   for (int i = 0; i < view->GetChildViewCount(); ++i)
-    RegisterChildrenForVisibleBoundsNotification(root, view->GetChildViewAt(i));
+    RegisterChildrenForRootNotifications(root, view->GetChildViewAt(i));
 }
 
 // static
-void View::UnregisterChildrenForVisibleBoundsNotification(
+void View::UnregisterChildrenForRootNotifications(
     RootView* root, View* view) {
   DCHECK(root && view);
   if (view->GetNotifyWhenVisibleBoundsInRootChanges())
     root->UnregisterViewForVisibleBoundsNotification(view);
+  if (view->near_insets_.get())
+    root->UnregisterViewForNearNotification(view);
   for (int i = 0; i < view->GetChildViewCount(); ++i)
-    UnregisterChildrenForVisibleBoundsNotification(root,
-                                                   view->GetChildViewAt(i));
+    UnregisterChildrenForRootNotifications(root, view->GetChildViewAt(i));
 }
 
 void View::AddDescendantToNotify(View* view) {
   DCHECK(view);
   if (!descendants_to_notify_.get())
     descendants_to_notify_.reset(new ViewList());
   descendants_to_notify_->push_back(view);
 }
 
 void View::RemoveDescendantToNotify(View* view) {
@@ skipping 13 matching lines @@
   possible_drag = false;
   start_pt = gfx::Point();
 }
 
 void View::DragInfo::PossibleDrag(const gfx::Point& p) {
   possible_drag = true;
   start_pt = p;
 }
 
 }  // namespace