cc: Split ReleaseResources into Release and Recreate.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 15059ba7d2782771774f19bdb197a90c43b34656..3a0753f5da627c156836ea8d7a77240927261e75 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -602,8 +602,12 @@ void PictureLayerImpl::DidBeginTracing() {
 void PictureLayerImpl::ReleaseResources() {
   // Recreate tilings with new settings, since some of those might change when
   // we release resources.
-  tilings_ = CreatePictureLayerTilingSet();
+  tilings_ = nullptr;
   ResetRasterScale();
+}
+
+void PictureLayerImpl::RecreateResources() {
+  tilings_ = CreatePictureLayerTilingSet();
 
   // To avoid an edge case after lost context where the tree is up to date but
   // the tilings have not been managed, request an update draw properties