Reset the root layer on the compositor when recreating a root layer.

ui/compositor/layer_owner_unittest.cc

 // Copyright 2014 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 "ui/compositor/layer_owner.h"
 
+#include "base/test/null_task_runner.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/compositor/compositor.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
+#include "ui/compositor/test/context_factories_for_test.h"
+#include "ui/gfx/native_widget_types.h"
 
 namespace ui {
 
 TEST(LayerOwnerTest, RecreateLayerHonorsTargetVisibilityAndOpacity) {
   LayerOwner owner;
   Layer* layer = new Layer;
   layer->SetVisible(true);
   layer->SetOpacity(1.0f);
 
   owner.SetLayer(layer);
 
   ScopedLayerAnimationSettings settings(layer->GetAnimator());
   layer->SetVisible(false);
   layer->SetOpacity(0.0f);
   EXPECT_TRUE(layer->visible());
   EXPECT_EQ(1.0f, layer->opacity());
 
   scoped_ptr<Layer> old_layer(owner.RecreateLayer());
   EXPECT_FALSE(owner.layer()->visible());
   EXPECT_EQ(0.0f, owner.layer()->opacity());
 }
 
+TEST(LayerOwnerTest, RecreateRootLayerWithNullCompositor) {
+  LayerOwner owner;
+  Layer* layer = new Layer;
+  owner.SetLayer(layer);
+
+  scoped_ptr<Layer> layer_copy = owner.RecreateLayer();
+
+  EXPECT_EQ(nullptr, owner.layer()->GetCompositor());
+  EXPECT_EQ(nullptr, layer_copy->GetCompositor());
+}
+
+TEST(LayerOwnerTest, RecreateRootLayerWithCompositor) {
+  LayerOwner owner;
+  Layer* layer = new Layer;
+  owner.SetLayer(layer);
+
+  ui::ContextFactory* context_factory =
+      ui::InitializeContextFactoryForTests(false);

[Lei Zhang, 2015/03/06 22:09:14]

Looks like you forgot to call TerminateContextFactoryForTests()

+  scoped_refptr<base::SingleThreadTaskRunner> task_runner =
+      new base::NullTaskRunner();
+  scoped_ptr<ui::Compositor> compositor(new ui::Compositor(
+      gfx::kNullAcceleratedWidget, context_factory, task_runner));
+  compositor->SetRootLayer(layer);
+
+  scoped_ptr<Layer> layer_copy = owner.RecreateLayer();
+
+  EXPECT_EQ(compositor.get(), owner.layer()->GetCompositor());
+  EXPECT_EQ(owner.layer(), compositor->root_layer());
+  EXPECT_EQ(nullptr, layer_copy->GetCompositor());
+}
+
 }  // namespace ui