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

cc/resources/raster_worker_pool.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/raster_worker_pool.h"
 
 #include "base/debug/trace_event_synthetic_delay.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
@@ skipping 105 matching lines @@
     // Record the solid color prediction.
     UMA_HISTOGRAM_BOOLEAN("Renderer4.SolidColorTilesAnalyzed",
                           analysis_.is_solid_color);
 
     // Clear the flag if we're not using the estimator.
     analysis_.is_solid_color &= kUseColorEstimator;
   }
 
   void RunRasterOnThread(unsigned thread_index,
                          void* buffer,
-                         gfx::Size size,
+                         const gfx::Size& size,
                          int stride) {
     TRACE_EVENT2(
         "cc",
         "RasterWorkerPoolTaskImpl::RunRasterOnThread",
         "data",
         TracedValue::FromValue(DataAsValue().release()),
         "raster_mode",
         TracedValue::FromValue(RasterModeAsValue(raster_mode_).release()));
 
     devtools_instrumentation::ScopedLayerTask raster_task(
@@ skipping 624 matching lines @@
 
     internal::GraphNode* decode_node =
         CreateGraphNodeForTask(decode_task, priority, graph);
     decode_node->add_dependent(raster_node);
   }
 
   return raster_node;
 }
 
 }  // namespace cc