Remove doublepointer in VirtualMethods, and from_borrowed_ref

Most of the heavy lifting done by:

```
$ ls *rs | xargs gawk -i inplace '/let .*: &&.*from_borrowed_ref/{sub("&&", "\\&");sub("_borrowed_","_");} {print $0}'
$ ls *rs | xargs gawk -i inplace "/impl.*VirtualMethods/{in_vm=1; sub(/<'a>/,\"\");sub(/&'a /,\"\")} /^}\$/{in_vm=0;} in_vm{\$0=gensub(/\\*self([^.])/,\"self\\\1\",\"g\"); sub(/from_borrowed_ref/,\"from_ref\")} {print}"
```

1 files changed, 3 insertions, 3 deletions

diff --git a/components/script/dom/htmlheadelement.rs b/components/script/dom/htmlheadelement.rs
index 0353ace6436..ce35a0e7286 100644
--- a/components/script/dom/htmlheadelement.rs
+++ b/components/script/dom/htmlheadelement.rs
@@ -46,12 +46,12 @@ impl HTMLHeadElement {
     }
 }
 
-impl<'a> VirtualMethods for &'a HTMLHeadElement {
+impl VirtualMethods for HTMLHeadElement {
     fn super_type<'b>(&'b self) -> Option<&'b VirtualMethods> {
-        let htmlelement: &&HTMLElement = HTMLElementCast::from_borrowed_ref(self);
+        let htmlelement: &HTMLElement = HTMLElementCast::from_ref(self);
         Some(htmlelement as &VirtualMethods)
     }
     fn bind_to_tree(&self, _tree_in_doc: bool) {
-        load_script(*self);
+        load_script(self);
     }
 }