cc::SharedQuadState: drop CopyFrom and add copy constructor

cc/quads/draw_quad_perftest.cc

 // Copyright 2015 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 <vector>
 
 #include "base/bind.h"
 #include "base/time/time.h"
 #include "cc/debug/lap_timer.h"
 #include "cc/quads/draw_quad.h"
@@ skipping 30 matching lines @@
   DrawQuadPerfTest()
       : timer_(kWarmupRuns,
                base::TimeDelta::FromMilliseconds(kTimeLimitMillis),
                kTimeCheckInterval) {}
 
   void CreateRenderPass() {
     render_pass_ = RenderPass::Create();
     SharedQuadState* new_shared_state(
         CreateSharedQuadState(render_pass_.get()));
     shared_state_ = render_pass_->CreateAndAppendSharedQuadState();
-    shared_state_->CopyFrom(new_shared_state);
+    *shared_state_ = *new_shared_state;
   }
 
   void CleanUpRenderPass() {
     render_pass_.reset();
     shared_state_ = nullptr;
   }
 
   void GenerateTextureDrawQuads(int count, std::vector<DrawQuad*>* quads) {
     for (int i = 0; i < count; ++i) {
       TextureDrawQuad* quad =
@@ skipping 42 matching lines @@
 };
 
 TEST_F(DrawQuadPerfTest, IterateResources) {
   RunIterateResourceTest("10_quads", 10);
   RunIterateResourceTest("100_quads", 100);
   RunIterateResourceTest("500_quads", 500);
 }
 
 }  // namespace
 }  // namespace cc