Move TrustedNodeAddress to script_layout_interface.

components/script_layout_interface/Cargo.toml

@@ -15,6 +15,7 @@ gfx_traits = {path = "../gfx_traits"}
 heapsize = "0.3.0"
 heapsize_plugin = "0.1.2"
 ipc-channel = {git = "https://github.com/servo/ipc-channel"}
+libc = "0.2"
 msg = {path = "../msg"}
 plugins = {path = "../plugins"}
 range = {path = "../range"}

components/script_layout_interface/lib.rs

@@ -22,6 +22,7 @@ extern crate core;
 extern crate gfx_traits;
 extern crate heapsize;
 extern crate ipc_channel;
+extern crate libc;
 extern crate msg;
 extern crate range;
 extern crate selectors;
@@ -36,6 +37,7 @@ pub mod wrapper_traits;
 use canvas_traits::CanvasMsg;
 use core::nonzero::NonZero;
 use ipc_channel::ipc::IpcSender;
+use libc::c_void;
 use restyle_damage::RestyleDamage;
 use std::cell::RefCell;
 use style::servo::PrivateStyleData;
@@ -87,3 +89,10 @@ pub struct HTMLCanvasData {
     pub width: u32,
     pub height: u32,
 }
+
+/// The address of a node known to be valid. These are sent from script to layout.
+#[derive(Clone, PartialEq, Eq, Copy)]
+pub struct TrustedNodeAddress(pub *const c_void);
+
+#[allow(unsafe_code)]
+unsafe impl Send for TrustedNodeAddress {}