cc::SharedQuadState: drop CopyFrom and add copy constructor

cc/ipc/cc_param_traits_unittest.cc

Index: cc/ipc/cc_param_traits_unittest.cc
diff --git a/cc/ipc/cc_param_traits_unittest.cc b/cc/ipc/cc_param_traits_unittest.cc
index dd19404d5ee1e8f9f38d8fc60bbd00baa4cb5eaf..b750427c48ac6d596fbd3dfe12e2cbd7e5bb5af2 100644
--- a/cc/ipc/cc_param_traits_unittest.cc
+++ b/cc/ipc/cc_param_traits_unittest.cc
@@ -299,7 +299,7 @@ TEST_F(CCParamTraitsTest, AllQuads) {
 
   SharedQuadState* shared_state1_cmp =
       pass_cmp->CreateAndAppendSharedQuadState();
-  shared_state1_cmp->CopyFrom(shared_state1_in);
+  *shared_state1_cmp = *shared_state1_in;
 
   DebugBorderDrawQuad* debugborder_in =
       pass_in->CreateAndAppendDrawQuad<DebugBorderDrawQuad>();
@@ -316,7 +316,7 @@ TEST_F(CCParamTraitsTest, AllQuads) {
                            arbitrary_blend_mode2, arbitrary_context_id2);
   SharedQuadState* shared_state2_cmp =
       pass_cmp->CreateAndAppendSharedQuadState();
-  shared_state2_cmp->CopyFrom(shared_state2_in);
+  *shared_state2_cmp = *shared_state2_in;
 
   RenderPassDrawQuad* renderpass_in =
       pass_in->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
@@ -335,7 +335,7 @@ TEST_F(CCParamTraitsTest, AllQuads) {
                            arbitrary_blend_mode3, arbitrary_context_id3);
   SharedQuadState* shared_state3_cmp =
       pass_cmp->CreateAndAppendSharedQuadState();
-  shared_state3_cmp->CopyFrom(shared_state3_in);
+  *shared_state3_cmp = *shared_state3_in;
 
   SolidColorDrawQuad* solidcolor_in =
       pass_in->CreateAndAppendDrawQuad<SolidColorDrawQuad>();