Add non-member non-mutating methods for common gfx::Rect operations.

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 173 matching lines @@
 
 std::string RootView::GetClassName() const {
   return kViewClassName;
 }
 
 void RootView::SchedulePaintInRect(const gfx::Rect& rect) {
   if (layer()) {
     layer()->SchedulePaint(rect);
   } else {
     gfx::Rect xrect = ConvertRectToParent(rect);
-    gfx::Rect invalid_rect = GetLocalBounds();
-    invalid_rect.Intersect(xrect);
+    gfx::Rect invalid_rect = gfx::Intersection(GetLocalBounds(), xrect);
     if (!invalid_rect.IsEmpty())
       widget_->SchedulePaintInRect(invalid_rect);
   }
 }
 
 bool RootView::OnMousePressed(const ui::MouseEvent& event) {
   UpdateCursor(event);
   SetMouseLocationAndFlags(event);
 
   // If mouse_pressed_handler_ is non null, we are currently processing
@@ skipping 408 matching lines @@
 }
 
 void RootView::SetMouseLocationAndFlags(const ui::MouseEvent& event) {
   last_mouse_event_flags_ = event.flags();
   last_mouse_event_x_ = event.x();
   last_mouse_event_y_ = event.y();
 }
 
 }  // namespace internal
 }  // namespace views