cc: Various code safety improvements in video compositing code.

cc/layers/video_layer_impl.cc

Index: cc/layers/video_layer_impl.cc
diff --git a/cc/layers/video_layer_impl.cc b/cc/layers/video_layer_impl.cc
index 228f2ccdc8404341b54770e8271d8dfad4e1f9e6..28037cca1587a420e7aaf62ac9694dbbaad1eae1 100644
--- a/cc/layers/video_layer_impl.cc
+++ b/cc/layers/video_layer_impl.cc
@@ -30,18 +30,23 @@ scoped_ptr<VideoLayerImpl> VideoLayerImpl::Create(
     int id,
     VideoFrameProvider* provider,
     media::VideoRotation video_rotation) {
-  scoped_ptr<VideoLayerImpl> layer(
-      new VideoLayerImpl(tree_impl, id, video_rotation));
-  layer->SetProviderClientImpl(VideoFrameProviderClientImpl::Create(provider));
-  DCHECK(tree_impl->proxy()->IsImplThread());
   DCHECK(tree_impl->proxy()->IsMainThreadBlocked());
-  return layer.Pass();
+  DCHECK(tree_impl->proxy()->IsImplThread());
+
+  scoped_refptr<VideoFrameProviderClientImpl> provider_client_impl =
+      VideoFrameProviderClientImpl::Create(provider);
+
+  return make_scoped_ptr(
+      new VideoLayerImpl(tree_impl, id, provider_client_impl, video_rotation));
 }
 
-VideoLayerImpl::VideoLayerImpl(LayerTreeImpl* tree_impl,
-                               int id,
-                               media::VideoRotation video_rotation)
+VideoLayerImpl::VideoLayerImpl(
+    LayerTreeImpl* tree_impl,
+    int id,
+    scoped_refptr<VideoFrameProviderClientImpl> provider_client_impl,
+    media::VideoRotation video_rotation)
     : LayerImpl(tree_impl, id),
+      provider_client_impl_(provider_client_impl),
       frame_(nullptr),
       video_rotation_(video_rotation) {
 }
@@ -61,18 +66,13 @@ VideoLayerImpl::~VideoLayerImpl() {
 
 scoped_ptr<LayerImpl> VideoLayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
-  return make_scoped_ptr(new VideoLayerImpl(tree_impl, id(), video_rotation_));
-}
-
-void VideoLayerImpl::PushPropertiesTo(LayerImpl* layer) {
-  LayerImpl::PushPropertiesTo(layer);
-
-  VideoLayerImpl* other = static_cast<VideoLayerImpl*>(layer);
-  other->SetProviderClientImpl(provider_client_impl_);
+  return make_scoped_ptr(new VideoLayerImpl(
+      tree_impl, id(), provider_client_impl_, video_rotation_));
 }
 
 void VideoLayerImpl::DidBecomeActive() {
-  provider_client_impl_->SetActiveVideoLayer(this);
+  if (!provider_client_impl_->Started())
+    provider_client_impl_->Start(this);
 }
 
 bool VideoLayerImpl::WillDraw(DrawMode draw_mode,
@@ -364,11 +364,6 @@ void VideoLayerImpl::SetNeedsRedraw() {
   layer_tree_impl()->SetNeedsRedraw();
 }
 
-void VideoLayerImpl::SetProviderClientImpl(
-    scoped_refptr<VideoFrameProviderClientImpl> provider_client_impl) {
-  provider_client_impl_ = provider_client_impl;
-}
-
 const char* VideoLayerImpl::LayerTypeAsString() const {
   return "cc::VideoLayerImpl";
 }