cc: Move gpu rasterization flag from LayerImpl to LayerTreeImpl.

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 9797c974b27798cd7a65185f67220914cb8220ad..78bb4a604c18f7befc066a8299facfdd686a2c76 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -332,6 +332,13 @@ void LayerTreeHostImpl::CommitComplete() {
   TRACE_EVENT0("cc", "LayerTreeHostImpl::CommitComplete");
 
   if (settings_.impl_side_painting) {
+    if (pending_tree_->use_gpu_rasterization() !=
+        active_tree_->use_gpu_rasterization()) {
+      // We need to recreate tilings for all layers in the pending tree.
+      // The tile size and rasterization is different for sw and gpu rasterizer.
+      SendReleaseResourcesRecursive(pending_tree_->root_layer());
+      // TODO(alokp): Rip out rasterizer delegate and switch rasterizers here.
+    }
     // Impl-side painting needs an update immediately post-commit to have the
     // opportunity to create tilings.  Other paths can call UpdateDrawProperties
     // more lazily when needed prior to drawing.