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

cc/resources/raster_worker_pool.cc

Index: cc/resources/raster_worker_pool.cc
diff --git a/cc/resources/raster_worker_pool.cc b/cc/resources/raster_worker_pool.cc
index 7403f6d26637507f663e39a878d82f191daa70a0..1114fcd35fb24f1db44471a1d861ec8643d4c166 100644
--- a/cc/resources/raster_worker_pool.cc
+++ b/cc/resources/raster_worker_pool.cc
@@ -121,7 +121,7 @@ class RasterWorkerPoolTaskImpl : public internal::RasterWorkerPoolTask {
 
   bool RunRasterOnThread(unsigned thread_index,
                          void* buffer,
-                         gfx::Size size,
+                         const gfx::Size& size,
                          int stride) {
     TRACE_EVENT2(
         "cc",
@@ -173,7 +173,7 @@ class RasterWorkerPoolTaskImpl : public internal::RasterWorkerPoolTask {
   // Overridden from internal::RasterWorkerPoolTask:
   virtual bool RunOnWorkerThread(unsigned thread_index,
                                  void* buffer,
-                                 gfx::Size size,
+                                 const gfx::Size& size,
                                  int stride) OVERRIDE {
     // TODO(alokp): For now run-on-worker-thread implies software rasterization.
     DCHECK(!use_gpu_rasterization());