[#4] Pass gfx structs by const ref (gfx::PointF)

cc/trees/layer_tree_host_unittest_occlusion.cc

 // Copyright 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 "cc/trees/layer_tree_host.h"
 
 #include "cc/layers/layer.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/output/copy_output_result.h"
 #include "cc/test/layer_tree_test.h"
@@ skipping 68 matching lines @@
 
     for (size_t i = 0; i < layer->children().size(); ++i) {
       TestLayer* child = static_cast<TestLayer*>(layer->children()[i].get());
       VerifyOcclusion(child);
     }
   }
 
   void SetLayerPropertiesForTesting(TestLayer* layer,
                                     TestLayer* parent,
                                     const gfx::Transform& transform,
-                                    gfx::PointF position,
+                                    const gfx::PointF& position,
                                     gfx::Size bounds,
                                     bool opaque) const {
     layer->RemoveAllChildren();
     if (parent)
       parent->AddChild(layer);
     layer->SetTransform(transform);
     layer->SetPosition(position);
     layer->SetBounds(bounds);
     layer->SetContentsOpaque(opaque);
 
@@ skipping 514 matching lines @@
 
     layer_tree_host()->SetRootLayer(layers[0]);
     LayerTreeTest::SetupTree();
   }
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostOcclusionTestManySurfaces);
 
 }  // namespace
 }  // namespace cc