Remove useless unsafe methods on LayoutJS<T>

components/layout/wrapper.rs

@@ -197,7 +197,7 @@ impl<'a> PartialEq for LayoutNode<'a> {
 impl<'ln> TLayoutNode for LayoutNode<'ln> {
     unsafe fn new_with_this_lifetime(&self, node: &LayoutJS<Node>) -> LayoutNode<'ln> {
         LayoutNode {
-            node: node.transmute_copy(),
+            node: *node,
             chain: self.chain,
         }
     }
@@ -728,10 +728,7 @@ impl<'ln> TLayoutNode for ThreadSafeLayoutNode<'ln> {
     /// Creates a new layout node with the same lifetime as this layout node.
     unsafe fn new_with_this_lifetime(&self, node: &LayoutJS<Node>) -> ThreadSafeLayoutNode<'ln> {
         ThreadSafeLayoutNode {
-            node: LayoutNode {
+            node: self.node.new_with_this_lifetime(node),
-                node: node.transmute_copy(),
-                chain: self.node.chain,
-            },
             pseudo: PseudoElementType::Normal,
         }
     }

components/script/dom/bindings/codegen/CodegenRust.py

@@ -5471,7 +5471,7 @@ impl ${name}Cast {
     pub fn to_layout_js<T: ${toBound}+Reflectable>(base: &LayoutJS<T>) -> Option<LayoutJS<${name}>> {
         unsafe {
             match (*base.unsafe_get()).${checkFn}() {
-                true => Some(base.transmute_copy()),
+                true => Some(mem::transmute_copy(base)),
                 false => None
             }
         }
@@ -5498,7 +5498,7 @@ impl ${name}Cast {
     #[inline(always)]
     #[allow(unrooted_must_root)]
     pub fn from_layout_js<T: ${fromBound}+Reflectable>(derived: &LayoutJS<T>) -> LayoutJS<${name}> {
-        unsafe { derived.transmute_copy() }
+        unsafe { mem::transmute_copy(derived) }
     }
 
     #[inline(always)]

components/script/dom/bindings/js.rs

@@ -64,7 +64,6 @@ use std::cell::{Cell, UnsafeCell};
 use std::default::Default;
 use std::intrinsics::return_address;
 use std::marker::PhantomData;
-use std::mem;
 use std::ops::Deref;
 
 /// An unrooted, JS-owned value. Must not be held across a GC.
@@ -431,13 +430,6 @@ impl<T: Reflectable> LayoutJS<T> {
     }
 }
 
-impl<From> LayoutJS<From> {
-    /// Return `self` as a `LayoutJS` of another type.
-    pub unsafe fn transmute_copy<To>(&self) -> LayoutJS<To> {
-        mem::transmute_copy(self)
-    }
-}
-
 /// Get an `Option<JSRef<T>>` out of an `Option<Root<T>>`
 pub trait RootedReference<T> {
     /// Obtain a safe optional reference to the wrapped JS owned-value that

components/script/dom/element.rs

@@ -389,7 +389,7 @@ impl LayoutElementHelpers for LayoutJS<Element> {
         if (*self.unsafe_get()).namespace != ns!(HTML) {
             return false
         }
-        let node: LayoutJS<Node> = self.transmute_copy();
+        let node = NodeCast::from_layout_js(&self);
         node.owner_doc_for_layout().is_html_document_for_layout()
     }
 

components/script/dom/htmlinputelement.rs

@@ -164,7 +164,7 @@ impl LayoutHTMLInputElementHelpers for LayoutJS<HTMLInputElement> {
 
         #[allow(unsafe_code)]
         unsafe fn get_raw_attr_value(input: LayoutJS<HTMLInputElement>) -> Option<String> {
-            let elem: LayoutJS<Element> = input.transmute_copy();
+            let elem = ElementCast::from_layout_js(&input);
             (*elem.unsafe_get()).get_attr_val_for_layout(&ns!(""), &atom!("value"))
                                 .map(|s| s.to_owned())
         }