Allow use of container cbegin() and cend() methods, plus sample uses.

ui/views/view_unittest.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 <stddef.h>
 
 #include <map>
 
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
@@ skipping 3413 matching lines @@
   EXPECT_EQ(NULL, v1.GetViewByID(kV5ID));  // No V5 exists.
   EXPECT_EQ(NULL, v2.GetViewByID(kV1ID));  // It can get only from child views.
 
   const int kGroup = 1;
   v3.SetGroup(kGroup);
   v4.SetGroup(kGroup);
 
   View::Views views;
   v1.GetViewsInGroup(kGroup, &views);
   EXPECT_EQ(2U, views.size());
-
-  View::Views::const_iterator i(std::find(views.begin(), views.end(), &v3));
-  EXPECT_NE(views.end(), i);
-
-  i = std::find(views.begin(), views.end(), &v4);
-  EXPECT_NE(views.end(), i);
+  EXPECT_NE(views.cend(), std::find(views.cbegin(), views.cend(), &v3));
+  EXPECT_NE(views.cend(), std::find(views.cbegin(), views.cend(), &v4));
 }
 
 TEST_F(ViewTest, AddExistingChild) {
   View v1, v2, v3;
 
   v1.AddChildView(&v2);
   v1.AddChildView(&v3);
   EXPECT_EQ(0, v1.GetIndexOf(&v2));
   EXPECT_EQ(1, v1.GetIndexOf(&v3));
 
@@ skipping 947 matching lines @@
 
   // The View should continue receiving events after the |handler| is deleted.
   v->Reset();
   ui::MouseEvent released(ui::ET_MOUSE_RELEASED, gfx::Point(), gfx::Point(),
                           ui::EventTimeForNow(), 0, 0);
   root->OnMouseReleased(released);
   EXPECT_EQ(ui::ET_MOUSE_RELEASED, v->last_mouse_event_type_);
 }
 
 }  // namespace views