[#2] Pass gfx structs by const ref (gfx::Rect, gfx::RectF)

cc/layers/tiled_layer_unittest.cc

 // Copyright 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 "cc/layers/tiled_layer.h"
 
 #include <limits>
 #include <vector>
 
 #include "cc/debug/overdraw_metrics.h"
@@ skipping 1825 matching lines @@
   layer_tree_host_->SetRootLayer(NULL);
 }
 
 class TrackingLayerPainter : public LayerPainter {
  public:
   static scoped_ptr<TrackingLayerPainter> Create() {
     return make_scoped_ptr(new TrackingLayerPainter());
   }
 
   virtual void Paint(SkCanvas* canvas,
-                     gfx::Rect content_rect,
+                     const gfx::Rect& content_rect,
                      gfx::RectF* opaque) OVERRIDE {
     painted_rect_ = content_rect;
   }
 
   gfx::Rect PaintedRect() const { return painted_rect_; }
   void ResetPaintedRect() { painted_rect_ = gfx::Rect(); }
 
  private:
   gfx::Rect painted_rect_;
 };
@@ skipping 90 matching lines @@
   // Invalidate the entire layer in layer space. When painting, the rect given
   // to webkit should match the layer's bounds.
   layer->SetNeedsDisplayRect(layer_rect);
   layer->Update(queue_.get(), NULL);
 
   EXPECT_RECT_EQ(layer_rect, layer->tracking_layer_painter()->PaintedRect());
 }
 
 }  // namespace
 }  // namespace cc