Revert of [#7] Pass gfx structs by const ref (gfx::Size)

cc/resources/picture_layer_tiling_set.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/resources/picture_layer_tiling_set.h"
 
 #include <limits>
 
 namespace cc {
 
 namespace {
 
 class LargestToSmallestScaleFunctor {
  public:
   bool operator() (PictureLayerTiling* left, PictureLayerTiling* right) {
     return left->contents_scale() > right->contents_scale();
   }
 };
 
 }  // namespace
 
 
 PictureLayerTilingSet::PictureLayerTilingSet(
     PictureLayerTilingClient* client,
-    const gfx::Size& layer_bounds)
+    gfx::Size layer_bounds)
     : client_(client),
       layer_bounds_(layer_bounds) {
 }
 
 PictureLayerTilingSet::~PictureLayerTilingSet() {
 }
 
 void PictureLayerTilingSet::SetClient(PictureLayerTilingClient* client) {
   client_ = client;
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->SetClient(client_);
 }
 
 void PictureLayerTilingSet::SyncTilings(
     const PictureLayerTilingSet& other,
-    const gfx::Size& new_layer_bounds,
+    gfx::Size new_layer_bounds,
     const Region& layer_invalidation,
     float minimum_contents_scale) {
   if (new_layer_bounds.IsEmpty()) {
     RemoveAllTilings();
     layer_bounds_ = new_layer_bounds;
     return;
   }
 
   tilings_.reserve(other.tilings_.size());
 
@@ skipping 244 matching lines @@
   return *this;
 }
 
 PictureLayerTilingSet::CoverageIterator::operator bool() const {
   return current_tiling_ < static_cast<int>(set_->tilings_.size()) ||
       region_iter_.has_rect();
 }
 
 void PictureLayerTilingSet::UpdateTilePriorities(
     WhichTree tree,
-    const gfx::Size& device_viewport,
+    gfx::Size device_viewport,
     const gfx::Rect& viewport_in_content_space,
     const gfx::Rect& visible_content_rect,
-    const gfx::Size& last_layer_bounds,
-    const gfx::Size& current_layer_bounds,
+    gfx::Size last_layer_bounds,
+    gfx::Size current_layer_bounds,
     float last_layer_contents_scale,
     float current_layer_contents_scale,
     const gfx::Transform& last_screen_transform,
     const gfx::Transform& current_screen_transform,
     double current_frame_time_in_seconds,
     size_t max_tiles_for_interest_area) {
   gfx::Rect viewport_in_layer_space = gfx::ScaleToEnclosingRect(
       viewport_in_content_space,
       1.f / current_layer_contents_scale);
   gfx::Rect visible_layer_rect = gfx::ScaleToEnclosingRect(
@@ skipping 35 matching lines @@
 }
 
 size_t PictureLayerTilingSet::GPUMemoryUsageInBytes() const {
   size_t amount = 0;
   for (size_t i = 0; i < tilings_.size(); ++i)
     amount += tilings_[i]->GPUMemoryUsageInBytes();
   return amount;
 }
 
 }  // namespace cc