[#3] Pass gfx structs by const ref (gfx::SizeF)

cc/input/page_scale_animation.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/input/page_scale_animation.h"
 
 #include <math.h>
 
 #include "base/logging.h"
 #include "cc/animation/timing_function.h"
 #include "ui/gfx/point_f.h"
 #include "ui/gfx/rect_f.h"
 #include "ui/gfx/vector2d_conversions.h"
 
 namespace {
 
 // This takes a viewport-relative vector and returns a vector whose values are
 // between 0 and 1, representing the percentage position within the viewport.
 gfx::Vector2dF NormalizeFromViewport(gfx::Vector2dF denormalized,
-                                     gfx::SizeF viewport_size) {
+                                     const gfx::SizeF& viewport_size) {
   return gfx::ScaleVector2d(denormalized,
                             1.f / viewport_size.width(),
                             1.f / viewport_size.height());
 }
 
 gfx::Vector2dF DenormalizeToViewport(gfx::Vector2dF normalized,
-                                     gfx::SizeF viewport_size) {
+                                     const gfx::SizeF& viewport_size) {
   return gfx::ScaleVector2d(normalized,
                             viewport_size.width(),
                             viewport_size.height());
 }
 
 gfx::Vector2dF InterpolateBetween(gfx::Vector2dF start,
                                   gfx::Vector2dF end,
                                   float interp) {
   return start + gfx::ScaleVector2d(end - start, interp);
 }
 
 }  // namespace
 
 namespace cc {
 
 scoped_ptr<PageScaleAnimation> PageScaleAnimation::Create(
     gfx::Vector2dF start_scroll_offset,
     float start_page_scale_factor,
-    gfx::SizeF viewport_size,
-    gfx::SizeF root_layer_size,
+    const gfx::SizeF& viewport_size,
+    const gfx::SizeF& root_layer_size,
     scoped_ptr<TimingFunction> timing_function) {
   return make_scoped_ptr(new PageScaleAnimation(start_scroll_offset,
                                                 start_page_scale_factor,
                                                 viewport_size,
                                                 root_layer_size,
                                                 timing_function.Pass()));
 }
 
 PageScaleAnimation::PageScaleAnimation(
     gfx::Vector2dF start_scroll_offset,
     float start_page_scale_factor,
-    gfx::SizeF viewport_size,
-    gfx::SizeF root_layer_size,
+    const gfx::SizeF& viewport_size,
+    const gfx::SizeF& root_layer_size,
     scoped_ptr<TimingFunction> timing_function)
     : start_page_scale_factor_(start_page_scale_factor),
       target_page_scale_factor_(0.f),
       start_scroll_offset_(start_scroll_offset),
       start_anchor_(),
       target_anchor_(),
       viewport_size_(viewport_size),
       root_layer_size_(root_layer_size),
       start_time_(-1.0),
       duration_(0.0),
@@ skipping 162 matching lines @@
 
   // Linearly interpolate the magnitude in log scale.
   float diff = target_page_scale_factor_ / start_page_scale_factor_;
   float log_diff = log(diff);
   log_diff *= interp;
   diff = exp(log_diff);
   return start_page_scale_factor_ * diff;
 }
 
 }  // namespace cc