Rename cc::ResourceProvider::ResourceId to cc::ResourceId and move it to its own file.

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 27688591420284b6853c22b0b7cb93350d623402..8e09910c0ad7890878c36d9df7924bf9050d5161 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -1098,8 +1098,7 @@ void LayerTreeImpl::set_ui_resource_request_queue(
   ui_resource_request_queue_ = queue;
 }
 
-ResourceProvider::ResourceId LayerTreeImpl::ResourceIdForUIResource(
-    UIResourceId uid) const {
+ResourceId LayerTreeImpl::ResourceIdForUIResource(UIResourceId uid) const {
   return layer_tree_host_impl_->ResourceIdForUIResource(uid);
 }