Make gfx::Rect class operations consistently mutate the class they are called on.

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 <map>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/rand_util.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 2001 matching lines @@
 
   void ClearScheduledPaintRect() {
     scheduled_paint_rect_ = gfx::Rect();
   }
 
   gfx::Rect scheduled_paint_rect() const { return scheduled_paint_rect_; }
 
   // Overridden from View:
   virtual void SchedulePaintInRect(const gfx::Rect& rect) {
     gfx::Rect xrect = ConvertRectToParent(rect);
-    scheduled_paint_rect_ = scheduled_paint_rect_.Union(xrect);
+    scheduled_paint_rect_.Union(xrect);
   }
 
  private:
   gfx::Rect scheduled_paint_rect_;
 
   DISALLOW_COPY_AND_ASSIGN(TransformPaintView);
 };
 
 TEST_F(ViewTest, TransformPaint) {
   TransformPaintView* v1 = new TransformPaintView();
@@ skipping 285 matching lines @@
   top_view.SetBoundsRect(gfx::Rect(0, 0, 100, 100));
   top_view.scheduled_paint_rects_.clear();
   child_view->SetBoundsRect(gfx::Rect(10, 10, 20, 20));
   top_view.AddChildView(child_view);
 
   top_view.scheduled_paint_rects_.clear();
   child_view->SetBoundsRect(gfx::Rect(30, 30, 20, 20));
   EXPECT_EQ(2U, top_view.scheduled_paint_rects_.size());
 
   // There should be 2 rects, spanning from (10, 10) to (50, 50).
-  gfx::Rect paint_rect =
-      top_view.scheduled_paint_rects_[0].Union(
-          top_view.scheduled_paint_rects_[1]);
+  gfx::Rect paint_rect = top_view.scheduled_paint_rects_[0];
+  paint_rect.Union(top_view.scheduled_paint_rects_[1]);
   EXPECT_EQ(gfx::Rect(10, 10, 40, 40), paint_rect);
 }
 
 // Tests conversion methods with a transform.
 TEST_F(ViewTest, ConvertPointToViewWithTransform) {
   TestView top_view;
   TestView* child = new TestView;
   TestView* child_child = new TestView;
 
   top_view.AddChildView(child);
@@ skipping 1046 matching lines @@
   // Set to non default value.
   v->layer()->set_scale_content(false);
   scoped_ptr<ui::Layer> old_layer(v->RecreateLayer());
   ui::Layer* new_layer = v->layer();
   EXPECT_FALSE(new_layer->scale_content());
 }
 
 #endif  // USE_AURA
 
 }  // namespace views