Auto merge of #7097 - boghison:memtypes, r=jdm

Measure heap memory usage for more types. Fixes #6951

Also adds HeapSizeOf implementations/derive for some types. I've used "Cannot calculate Heap size" as a reason everywhere, because my imagination is rather limited. If you'd like me to change this message for specific types, please write something like this: "Trusted - Cannot calculate Heap size for Trusted" so that it would be easier for me to replace them through a script :)

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components/script/dom/bindings/error.rs

@@ -9,6 +9,7 @@ use dom::bindings::conversions::ToJSValConvertible;
 use dom::bindings::global::GlobalRef;
 use dom::domexception::{DOMException, DOMErrorName};
 
+use util::mem::HeapSizeOf;
 use util::str::DOMString;
 
 use js::jsapi::{JSContext, JSObject, RootedValue};
@@ -24,7 +25,7 @@ use std::ptr;
 use std::mem;
 
 /// DOM exceptions that can be thrown by a native DOM method.
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, HeapSizeOf)]
 pub enum Error {
     /// IndexSizeError DOMException
     IndexSize,

components/script/dom/bindings/global.rs

@@ -27,6 +27,8 @@ use js::jsapi::{GetGlobalForObjectCrossCompartment};
 use js::jsapi::{JSContext, JSObject, JS_GetClass, MutableHandleValue};
 use url::Url;
 
+use util::mem::HeapSizeOf;
+
 /// A freely-copyable reference to a rooted global object.
 #[derive(Copy, Clone)]
 pub enum GlobalRef<'a> {
@@ -47,7 +49,7 @@ pub enum GlobalRoot {
 
 /// A traced reference to a global object, for use in fields of traced Rust
 /// structures.
-#[derive(JSTraceable)]
+#[derive(JSTraceable, HeapSizeOf)]
 #[must_root]
 pub enum GlobalField {
     /// A field for a `Window` object.

components/script/dom/bindings/js.rs

@@ -463,4 +463,3 @@ impl<T: Reflectable> Drop for Root<T> {
         unsafe { (*self.root_list).unroot(self); }
     }
 }
-

components/script/dom/bindings/str.rs

@@ -11,8 +11,10 @@ use std::ops;
 use std::str;
 use std::str::FromStr;
 
+use util::mem::HeapSizeOf;
+
 /// Encapsulates the IDL `ByteString` type.
-#[derive(JSTraceable,Clone,Eq,PartialEq)]
+#[derive(JSTraceable, Clone, Eq, PartialEq, HeapSizeOf)]
 pub struct ByteString(Vec<u8>);
 
 impl ByteString {