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

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 {
 
@@ skipping 129 matching lines @@
 }
 
 void PictureLayerTilingSet::RemoveAllTiles() {
   for (size_t i = 0; i < tilings_.size(); ++i)
     tilings_[i]->Reset();
 }
 
 PictureLayerTilingSet::CoverageIterator::CoverageIterator(
     const PictureLayerTilingSet* set,
     float contents_scale,
-    gfx::Rect content_rect,
+    const gfx::Rect& content_rect,
     float ideal_contents_scale)
     : set_(set),
       contents_scale_(contents_scale),
       ideal_contents_scale_(ideal_contents_scale),
       current_tiling_(-1) {
   missing_region_.Union(content_rect);
 
   for (ideal_tiling_ = 0;
        static_cast<size_t>(ideal_tiling_) < set_->tilings_.size();
        ++ideal_tiling_) {
@@ skipping 136 matching lines @@
 }
 
 PictureLayerTilingSet::CoverageIterator::operator bool() const {
   return current_tiling_ < static_cast<int>(set_->tilings_.size()) ||
       region_iter_.has_rect();
 }
 
 void PictureLayerTilingSet::UpdateTilePriorities(
     WhichTree tree,
     gfx::Size device_viewport,
-    gfx::Rect viewport_in_content_space,
-    gfx::Rect visible_content_rect,
+    const gfx::Rect& viewport_in_content_space,
+    const gfx::Rect& visible_content_rect,
     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,
@@ skipping 37 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