cc: Pass LayerTreeHostImpl to LayerImpl constructor

cc/layer_impl.cc

Index: cc/layer_impl.cc
diff --git a/cc/layer_impl.cc b/cc/layer_impl.cc
index 2b78195fbc6bf305b71266bd4dc040ca8c25fe9b..21500a5380476634bf3174b1be9d6732a35e6c8f 100644
--- a/cc/layer_impl.cc
+++ b/cc/layer_impl.cc
@@ -18,12 +18,12 @@
 
 namespace cc {
 
-LayerImpl::LayerImpl(int id)
+LayerImpl::LayerImpl(LayerTreeHostImpl* hostImpl, int id)
     : m_parent(0)
     , m_maskLayerId(-1)
     , m_replicaLayerId(-1)
     , m_layerId(id)
-    , m_layerTreeHostImpl(0)
+    , m_layerTreeHostImpl(hostImpl)
     , m_anchorPoint(0.5, 0.5)
     , m_anchorPointZ(0)
     , m_contentsScaleX(1.0)
@@ -53,6 +53,7 @@ LayerImpl::LayerImpl(int id)
     , m_layerAnimationController(LayerAnimationController::create(this))
 {
     DCHECK(m_layerId > 0);
+    DCHECK(m_layerTreeHostImpl);
 }
 
 LayerImpl::~LayerImpl()
@@ -65,6 +66,7 @@ LayerImpl::~LayerImpl()
 void LayerImpl::addChild(scoped_ptr<LayerImpl> child)
 {
     child->setParent(this);
+    DCHECK_EQ(layerTreeHostImpl(), child->layerTreeHostImpl());
     m_children.append(child.Pass());
 }
 
@@ -146,8 +148,6 @@ void LayerImpl::didDraw(ResourceProvider*)
 
 bool LayerImpl::showDebugBorders() const
 {
-    if (!m_layerTreeHostImpl)
-        return false;
     return m_layerTreeHostImpl->debugState().showDebugBorders;
 }
 
@@ -450,6 +450,8 @@ void LayerImpl::setBounds(const gfx::Size& bounds)
 
 void LayerImpl::setMaskLayer(scoped_ptr<LayerImpl> maskLayer)
 {
+    if (maskLayer)
+        DCHECK_EQ(layerTreeHostImpl(), maskLayer->layerTreeHostImpl());
     m_maskLayer = maskLayer.Pass();
 
     int newLayerId = m_maskLayer ? m_maskLayer->id() : -1;
@@ -462,6 +464,8 @@ void LayerImpl::setMaskLayer(scoped_ptr<LayerImpl> maskLayer)
 
 void LayerImpl::setReplicaLayer(scoped_ptr<LayerImpl> replicaLayer)
 {
+    if (replicaLayer)
+        DCHECK_EQ(layerTreeHostImpl(), replicaLayer->layerTreeHostImpl());
     m_replicaLayer = replicaLayer.Pass();
 
     int newLayerId = m_replicaLayer ? m_replicaLayer->id() : -1;