cc: Make LayerTreeHost a protected Layer member.

cc/layers/layer_unittest.cc

Index: cc/layers/layer_unittest.cc
diff --git a/cc/layers/layer_unittest.cc b/cc/layers/layer_unittest.cc
index 933df2b7095b9f28d2fcf7cd8d3962cd5a46ebbc..46818fa3b1a86e4e84cfbf1b8a7743abccd54b24 100644
--- a/cc/layers/layer_unittest.cc
+++ b/cc/layers/layer_unittest.cc
@@ -58,7 +58,7 @@ using ::testing::_;
 
 #define EXECUTE_AND_VERIFY_SUBTREE_CHANGED(code_to_test)                       \
   code_to_test;                                                                \
-  root->layer_tree_host()->BuildPropertyTreesForTesting();                     \
+  root->GetLayerTree()->BuildPropertyTreesForTesting();                        \
   EXPECT_TRUE(root->subtree_property_changed());                               \
   EXPECT_TRUE(                                                                 \
       root->GetLayerTree()->LayerNeedsPushPropertiesForTesting(root.get()));   \
@@ -84,7 +84,7 @@ using ::testing::_;
 
 #define EXECUTE_AND_VERIFY_ONLY_LAYER_CHANGED(code_to_test)                    \
   code_to_test;                                                                \
-  root->layer_tree_host()->BuildPropertyTreesForTesting();                     \
+  root->GetLayerTree()->BuildPropertyTreesForTesting();                        \
   EXPECT_TRUE(root->layer_property_changed());                                 \
   EXPECT_FALSE(root->subtree_property_changed());                              \
   EXPECT_TRUE(                                                                 \
@@ -1889,7 +1889,7 @@ class LayerTreeHostFactory {
 };
 
 void AssertLayerTreeHostMatchesForSubtree(Layer* layer, LayerTreeHost* host) {
-  EXPECT_EQ(host, layer->layer_tree_host());
+  EXPECT_EQ(host, layer->GetLayerTreeHostForTesting());
 
   for (size_t i = 0; i < layer->children().size(); ++i)
     AssertLayerTreeHostMatchesForSubtree(layer->children()[i].get(), host);
@@ -1943,7 +1943,7 @@ TEST_F(LayerLayerTreeHostTest, AddingLayerSubtree) {
 
   layer_tree->SetRootLayer(parent.get());
 
-  EXPECT_EQ(parent->layer_tree_host(), layer_tree_host.get());
+  EXPECT_EQ(parent->GetLayerTreeHostForTesting(), layer_tree_host.get());
 
   // Adding a subtree to a layer already associated with a host should set the
   // host pointer on all layers in that subtree.
@@ -2023,9 +2023,10 @@ TEST_F(LayerLayerTreeHostTest, ChangeHostInSubtree) {
   second_parent->AddChild(second_child);
 
   // The moved layer and its children should point to the new host.
-  EXPECT_EQ(second_layer_tree_host.get(), second_child->layer_tree_host());
   EXPECT_EQ(second_layer_tree_host.get(),
-            second_grand_child->layer_tree_host());
+            second_child->GetLayerTreeHostForTesting());
+  EXPECT_EQ(second_layer_tree_host.get(),
+            second_grand_child->GetLayerTreeHostForTesting());
 
   // Test over, cleanup time.
   first_layer_tree_host->GetLayerTree()->SetRootLayer(nullptr);
@@ -2054,13 +2055,13 @@ TEST_F(LayerLayerTreeHostTest, ReplaceMaskAndReplicaLayer) {
 
   // Replacing the mask should clear out the old mask's subtree's host pointers.
   parent->SetMaskLayer(mask_replacement.get());
-  EXPECT_EQ(nullptr, mask->layer_tree_host());
-  EXPECT_EQ(nullptr, mask_child->layer_tree_host());
+  EXPECT_EQ(nullptr, mask->GetLayerTreeHostForTesting());
+  EXPECT_EQ(nullptr, mask_child->GetLayerTreeHostForTesting());
 
   // Same for replacing a replica layer.
   parent->SetReplicaLayer(replica_replacement.get());
-  EXPECT_EQ(nullptr, replica->layer_tree_host());
-  EXPECT_EQ(nullptr, replica_child->layer_tree_host());
+  EXPECT_EQ(nullptr, replica->GetLayerTreeHostForTesting());
+  EXPECT_EQ(nullptr, replica_child->GetLayerTreeHostForTesting());
 
   // Test over, cleanup time.
   layer_tree_host->GetLayerTree()->SetRootLayer(nullptr);
@@ -2093,7 +2094,7 @@ TEST_F(LayerTest, SafeOpaqueBackgroundColor) {
                                                      : SK_ColorTRANSPARENT);
 
         layer_tree->property_trees()->needs_rebuild = true;
-        layer_tree_host->BuildPropertyTreesForTesting();
+        layer_tree_host->GetLayerTree()->BuildPropertyTreesForTesting();
         SkColor safe_color = layer->SafeOpaqueBackgroundColor();
         if (contents_opaque) {
           EXPECT_EQ(SkColorGetA(safe_color), 255u)