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

cc/layers/picture_layer_impl.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/layers/picture_layer_impl.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/time/time.h"
@@ skipping 450 matching lines @@
     bool should_use_gpu_rasterization) {
   if (should_use_gpu_rasterization != should_use_gpu_rasterization_) {
     should_use_gpu_rasterization_ = should_use_gpu_rasterization;
     RemoveAllTilings();
   } else {
     should_use_gpu_rasterization_ = should_use_gpu_rasterization;
   }
 }
 
 scoped_refptr<Tile> PictureLayerImpl::CreateTile(PictureLayerTiling* tiling,
-                                                 gfx::Rect content_rect) {
+                                               const gfx::Rect& content_rect) {
   if (!pile_->CanRaster(tiling->contents_scale(), content_rect))
     return scoped_refptr<Tile>();
 
   int flags = 0;
   if (is_using_lcd_text_)
     flags |= Tile::USE_LCD_TEXT;
   if (should_use_gpu_rasterization())
     flags |= Tile::USE_GPU_RASTERIZATION;
   return layer_tree_impl()->tile_manager()->CreateTile(
       pile_.get(),
@@ skipping 290 matching lines @@
     // content.
     MarkVisibleTilesAsRequired(
         low_res, twin_low_res, contents_scale_x(), rect, missing_region);
   }
 }
 
 bool PictureLayerImpl::MarkVisibleTilesAsRequired(
     PictureLayerTiling* tiling,
     const PictureLayerTiling* optional_twin_tiling,
     float contents_scale,
-    gfx::Rect rect,
+    const gfx::Rect& rect,
     const Region& missing_region) const {
   bool twin_had_missing_tile = false;
   for (PictureLayerTiling::CoverageIterator iter(tiling,
                                                  contents_scale,
                                                  rect);
        iter;
        ++iter) {
     Tile* tile = *iter;
     // A null tile (i.e. missing recording) can just be skipped.
     if (!tile)
@@ skipping 437 matching lines @@
 size_t PictureLayerImpl::GPUMemoryUsageInBytes() const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   return tilings_->GPUMemoryUsageInBytes();
 }
 
 void PictureLayerImpl::RunMicroBenchmark(MicroBenchmarkImpl* benchmark) {
   benchmark->RunOnLayer(this);
 }
 
 }  // namespace cc