Setup LayerTree class, refactor 2 functions from LayerTreeHost to it.

cc/layers/layer_unittest.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/layers/layer.h"
 
 #include <stddef.h>
 
 #include "base/threading/thread_task_runner_handle.h"
 #include "cc/animation/animation_host.h"
@@ skipping 125 matching lines @@
     // Serialize |src| to protobuf and read the first entry in the
     // LayerUpdate. There are no descendants, so the serialization
     // of |src| is the only entry.
     proto::LayerUpdate layer_update;
     src->ToLayerPropertiesProto(&layer_update);
     ASSERT_EQ(1, layer_update.layers_size());
     proto::LayerProperties props = layer_update.layers(0);
 
     // The |dest| layer needs to be able to lookup the scroll and clip parents.
     if (src->inputs_.scroll_parent)
-      layer_tree_host_->RegisterLayer(src->inputs_.scroll_parent);
+      layer_tree_host_->GetLayerTree()->RegisterLayer(
+          src->inputs_.scroll_parent);
     if (src->scroll_children_) {
       for (auto* child : *(src->scroll_children_))
-        layer_tree_host_->RegisterLayer(child);
+        layer_tree_host_->GetLayerTree()->RegisterLayer(child);
     }
     if (src->inputs_.clip_parent)
-      layer_tree_host_->RegisterLayer(src->inputs_.clip_parent);
+      layer_tree_host_->GetLayerTree()->RegisterLayer(src->inputs_.clip_parent);
     if (src->clip_children_) {
       for (auto* child : *(src->clip_children_))
-        layer_tree_host_->RegisterLayer(child);
+        layer_tree_host_->GetLayerTree()->RegisterLayer(child);
     }
     // Reset the LayerTreeHost registration for the |src| layer so
     // it can be re-used for the |dest| layer.
     src->SetLayerTreeHost(nullptr);
 
     scoped_refptr<Layer> dest = Layer::Create();
     dest->inputs_.layer_id = src->inputs_.layer_id;
     dest->SetLayerTreeHost(layer_tree_host_.get());
     dest->FromLayerPropertiesProto(props);
 
@@ skipping 77 matching lines @@
     }
 
     // The following member should have been reset during serialization.
     EXPECT_EQ(gfx::Rect(), src->inputs_.update_rect);
 
     // Before deleting |dest|, the LayerTreeHost must be unset.
     dest->SetLayerTreeHost(nullptr);
 
     // Cleanup scroll tree.
     if (src->inputs_.scroll_parent)
-      layer_tree_host_->UnregisterLayer(src->inputs_.scroll_parent);
+      layer_tree_host_->GetLayerTree()->UnregisterLayer(
+          src->inputs_.scroll_parent);
     src->inputs_.scroll_parent = nullptr;
     dest->inputs_.scroll_parent = nullptr;
     if (src->scroll_children_) {
       for (auto* child : *(src->scroll_children_))
-        layer_tree_host_->UnregisterLayer(child);
+        layer_tree_host_->GetLayerTree()->UnregisterLayer(child);
       src->scroll_children_.reset();
       dest->scroll_children_.reset();
     }
 
     // Cleanup clip tree.
     if (src->inputs_.clip_parent)
-      layer_tree_host_->UnregisterLayer(src->inputs_.clip_parent);
+      layer_tree_host_->GetLayerTree()->UnregisterLayer(
+          src->inputs_.clip_parent);
     src->inputs_.clip_parent = nullptr;
     dest->inputs_.clip_parent = nullptr;
     if (src->clip_children_) {
       for (auto* child : *(src->clip_children_))
-        layer_tree_host_->UnregisterLayer(child);
+        layer_tree_host_->GetLayerTree()->UnregisterLayer(child);
       src->clip_children_.reset();
       dest->clip_children_.reset();
     }
   }
 
   void RunNoMembersChangedTest() {
     scoped_refptr<Layer> layer = Layer::Create();
     VerifyBaseLayerPropertiesSerializationAndDeserialization(layer.get());
   }
 
@@ skipping 2253 matching lines @@
   EXPECT_EQ(MutableProperty::kNone, impl_layer->mutable_properties());
 
   test_layer->PushPropertiesTo(impl_layer.get());
 
   EXPECT_EQ(ElementId(2, 0), impl_layer->element_id());
   EXPECT_EQ(MutableProperty::kTransform, impl_layer->mutable_properties());
 }
 
 }  // namespace
 }  // namespace cc