ui: Add methods to Rect classes to get points at each of the rect's corners.

ui/gfx/rect_unittest.cc

 // Copyright (c) 2011 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 "base/basictypes.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/skia_util.h"
 
@@ skipping 725 matching lines @@
   EXPECT_EQ(RectF(2.2f, 1.1f, 3.3f, 4.4f).ToString(),
             (Vector2dF(1.1f, -1.1f) + f).ToString());
   f += Vector2dF(1.1f, -1.1f);
   EXPECT_EQ(RectF(2.2f, 1.1f, 3.3f, 4.4f).ToString(), f.ToString());
   EXPECT_EQ(RectF(1.1f, 2.2f, 3.3f, 4.4f).ToString(),
             (f - Vector2dF(1.1f, -1.1f)).ToString());
   f -= Vector2dF(1.1f, -1.1f);
   EXPECT_EQ(RectF(1.1f, 2.2f, 3.3f, 4.4f).ToString(), f.ToString());
 }
 
+TEST(RectTest, Corners) {
+  Rect i(1, 2, 3, 4);
+  RectF f(1.1f, 2.1f, 3.1f, 4.1f);
+
+  EXPECT_EQ(Point(1, 2).ToString(), i.TopLeft().ToString());
+  EXPECT_EQ(Point(4, 2).ToString(), i.TopRight().ToString());
+  EXPECT_EQ(Point(1, 6).ToString(), i.BottomLeft().ToString());
+  EXPECT_EQ(Point(4, 6).ToString(), i.BottomRight().ToString());
+
+  EXPECT_EQ(PointF(1.1f, 2.1f).ToString(), f.TopLeft().ToString());
+  EXPECT_EQ(PointF(4.2f, 2.1f).ToString(), f.TopRight().ToString());
+  EXPECT_EQ(PointF(1.1f, 6.2f).ToString(), f.BottomLeft().ToString());
+  EXPECT_EQ(PointF(4.2f, 6.2f).ToString(), f.BottomRight().ToString());
+}
+
 }  // namespace gfx