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

cc/test/layer_test_common.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/test/layer_test_common.h"
 
 #include "cc/base/math_util.h"
 #include "cc/base/region.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/render_pass.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/point_conversions.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/size_conversions.h"
 
 namespace cc {
 
 // Align with expected and actual output.
 const char* LayerTestCommon::quad_string = "    Quad: ";
 
-static bool CanRectFBeSafelyRoundedToRect(gfx::RectF r) {
+static bool CanRectFBeSafelyRoundedToRect(const gfx::RectF& r) {
   // Ensure that range of float values is not beyond integer range.
   if (!r.IsExpressibleAsRect())
     return false;
 
   // Ensure that the values are actually integers.
   if (gfx::ToFlooredPoint(r.origin()) == r.origin() &&
       gfx::ToFlooredSize(r.size()) == r.size())
     return true;
 
   return false;
 }
 
 void LayerTestCommon::VerifyQuadsExactlyCoverRect(const QuadList& quads,
-                                                  gfx::Rect rect) {
+                                                  const gfx::Rect& rect) {
   Region remaining = rect;
 
   for (size_t i = 0; i < quads.size(); ++i) {
     DrawQuad* quad = quads[i];
     gfx::RectF quad_rectf =
         MathUtil::MapClippedRect(quad->quadTransform(), gfx::RectF(quad->rect));
 
     // Before testing for exact coverage in the integer world, assert that
     // rounding will not round the rect incorrectly.
     ASSERT_TRUE(CanRectFBeSafelyRoundedToRect(quad_rectf));
 
     gfx::Rect quad_rect = gfx::ToEnclosingRect(quad_rectf);
 
     EXPECT_TRUE(rect.Contains(quad_rect)) << quad_string << i;
     EXPECT_TRUE(remaining.Contains(quad_rect)) << quad_string << i;
     remaining.Subtract(quad_rect);
   }
 
   EXPECT_TRUE(remaining.IsEmpty());
 }
 
 }  // namespace cc