cc: Don't pass simple well-defined classes by reference.

cc/resources/picture_pile_base.cc

 // Copyright 2013 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_pile_base.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 99 matching lines @@
   //
   // For example, if a 1/4 contents scale is used, then that would be 3 buffer
   // pixels, since that's the minimum number of pixels to add so that resulting
   // content can be snapped to a four pixel aligned grid.
   int buffer_pixels = static_cast<int>(ceil(1 / min_contents_scale) - 1);
   buffer_pixels = std::max(0, buffer_pixels);
   SetBufferPixels(buffer_pixels);
   min_contents_scale_ = min_contents_scale;
 }
 
-void PicturePileBase::SetTileGridSize(const gfx::Size& tile_grid_size) {
+void PicturePileBase::SetTileGridSize(gfx::Size tile_grid_size) {
   tile_grid_info_.fTileInterval.set(
       tile_grid_size.width() - 2 * kTileGridBorderPixels,
       tile_grid_size.height() - 2 * kTileGridBorderPixels);
   DCHECK_GT(tile_grid_info_.fTileInterval.width(), 0);
   DCHECK_GT(tile_grid_info_.fTileInterval.height(), 0);
   tile_grid_info_.fMargin.set(kTileGridBorderPixels,
       kTileGridBorderPixels);
   // Offset the tile grid coordinate space to take into account the fact
   // that the top-most and left-most tiles do not have top and left borders
   // respectively.
@@ skipping 36 matching lines @@
 bool PicturePileBase::CanRaster(float contents_scale, gfx::Rect content_rect) {
   if (tiling_.total_size().IsEmpty())
     return false;
   gfx::Rect layer_rect = gfx::ToEnclosingRect(
       gfx::ScaleRect(content_rect, 1.f / contents_scale));
   layer_rect.Intersect(gfx::Rect(tiling_.total_size()));
   return recorded_region_.Contains(layer_rect);
 }
 
 }  // namespace cc