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

cc/test/layer_tree_test.cc

 // Copyright 2011 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/test/layer_tree_test.h"
 
 #include "base/command_line.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_registrar.h"
 #include "cc/animation/layer_animation_controller.h"
@@ skipping 353 matching lines @@
       base::Bind(&LayerTreeTest::DispatchAcquireLayerTextures,
                  main_thread_weak_ptr_));
 }
 
 void LayerTreeTest::PostSetNeedsRedrawToMainThread() {
   proxy()->MainThread()->PostTask(
       base::Bind(&LayerTreeTest::DispatchSetNeedsRedraw,
                  main_thread_weak_ptr_));
 }
 
-void LayerTreeTest::PostSetNeedsRedrawRectToMainThread(
-    const gfx::Rect& damage_rect) {
+void LayerTreeTest::PostSetNeedsRedrawRectToMainThread(gfx::Rect damage_rect) {
   proxy()->MainThread()->PostTask(
       base::Bind(&LayerTreeTest::DispatchSetNeedsRedrawRect,
                  main_thread_weak_ptr_, damage_rect));
 }
 
 void LayerTreeTest::PostSetVisibleToMainThread(bool visible) {
   proxy()->MainThread()->PostTask(
       base::Bind(&LayerTreeTest::DispatchSetVisible,
                  main_thread_weak_ptr_,
                  visible));
@@ skipping 109 matching lines @@
     layer_tree_host_->AcquireLayerTextures();
 }
 
 void LayerTreeTest::DispatchSetNeedsRedraw() {
   DCHECK(!proxy() || proxy()->IsMainThread());
 
   if (layer_tree_host_)
     layer_tree_host_->SetNeedsRedraw();
 }
 
-void LayerTreeTest::DispatchSetNeedsRedrawRect(const gfx::Rect& damage_rect) {
+void LayerTreeTest::DispatchSetNeedsRedrawRect(gfx::Rect damage_rect) {
   DCHECK(!proxy() || proxy()->IsMainThread());
 
   if (layer_tree_host_)
     layer_tree_host_->SetNeedsRedrawRect(damage_rect);
 }
 
 void LayerTreeTest::DispatchSetVisible(bool visible) {
   DCHECK(!proxy() || proxy()->IsMainThread());
 
   if (!layer_tree_host_)
@@ skipping 58 matching lines @@
   ASSERT_FALSE(layer_tree_host_.get());
   client_.reset();
   if (timed_out_) {
     FAIL() << "Test timed out";
     return;
   }
   AfterTest();
 }
 
 }  // namespace cc