Replace all uses of the heapsize crate with malloc_size_of.

Servo currently uses `heapsize`, but Stylo/Gecko use `malloc_size_of`.
`malloc_size_of` is better -- it handles various cases that `heapsize` does not
-- so this patch changes Servo to use `malloc_size_of`.

This patch makes the following changes to the `malloc_size_of` crate.

- Adds `MallocSizeOf` trait implementations for numerous types, some built-in
  (e.g. `VecDeque`), some external and Servo-only (e.g. `string_cache`).

- Makes `enclosing_size_of_op` optional, because vanilla jemalloc doesn't
  support that operation.

- For `HashSet`/`HashMap`, falls back to a computed estimate when
  `enclosing_size_of_op` isn't available.

- Adds an extern "C" `malloc_size_of` function that does the actual heap
  measurement; this is based on the same functions from the `heapsize` crate.

This patch makes the following changes elsewhere.

- Converts all the uses of `heapsize` to instead use `malloc_size_of`.

- Disables the "heapsize"/"heap_size" feature for the external crates that
  provide it.

- Removes the `HeapSizeOf` implementation from `hashglobe`.

- Adds `ignore` annotations to a few `Rc`/`Arc`, because `malloc_size_of`
  doesn't derive those types, unlike `heapsize`.

components/style/servo/media_queries.rs

@@ -27,7 +27,7 @@ use values::specified;
 /// is displayed in.
 ///
 /// This is the struct against which media queries are evaluated.
-#[derive(HeapSizeOf)]
+#[derive(MallocSizeOf)]
 pub struct Device {
     /// The current media type used by de device.
     media_type: MediaType,
@@ -44,14 +44,14 @@ pub struct Device {
     /// other style being computed at the same time, given we need the style of
     /// the parent to compute everything else. So it is correct to just use
     /// a relaxed atomic here.
-    #[ignore_heap_size_of = "Pure stack type"]
+    #[ignore_malloc_size_of = "Pure stack type"]
     root_font_size: AtomicIsize,
     /// Whether any styles computed in the document relied on the root font-size
     /// by using rem units.
-    #[ignore_heap_size_of = "Pure stack type"]
+    #[ignore_malloc_size_of = "Pure stack type"]
     used_root_font_size: AtomicBool,
     /// Whether any styles computed in the document relied on the viewport size.
-    #[ignore_heap_size_of = "Pure stack type"]
+    #[ignore_malloc_size_of = "Pure stack type"]
     used_viewport_units: AtomicBool,
 }
 
@@ -153,7 +153,7 @@ impl Device {
 ///
 /// Only `pub` for unit testing, please don't use it directly!
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub enum ExpressionKind {
     /// <http://dev.w3.org/csswg/mediaqueries-3/#width>
     Width(Range<specified::Length>),
@@ -163,7 +163,7 @@ pub enum ExpressionKind {
 ///
 /// <http://dev.w3.org/csswg/mediaqueries-3/#media1>
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct Expression(pub ExpressionKind);
 
 impl Expression {
@@ -240,7 +240,7 @@ impl ToCss for Expression {
 /// Only public for testing, implementation details of `Expression` may change
 /// for Stylo.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub enum Range<T> {
     /// At least the inner value.
     Min(T),

components/style/servo/restyle_damage.rs

@@ -8,7 +8,6 @@
 #![deny(missing_docs)]
 
 use computed_values::display;
-use heapsize::HeapSizeOf;
 use matching::{StyleChange, StyleDifference};
 use properties::ComputedValues;
 use std::fmt;
@@ -53,9 +52,7 @@ bitflags! {
     }
 }
 
-impl HeapSizeOf for ServoRestyleDamage {
-    fn heap_size_of_children(&self) -> usize { 0 }
-}
+malloc_size_of_is_0!(ServoRestyleDamage);
 
 impl ServoRestyleDamage {
     /// Compute the `StyleDifference` (including the appropriate restyle damage)

components/style/servo/selector_parser.rs

@@ -30,7 +30,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
 ///
 /// NB: If you add to this list, be sure to update `each_simple_pseudo_element` too.
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 #[allow(missing_docs)]
 #[repr(usize)]
 pub enum PseudoElement {
@@ -251,7 +251,7 @@ pub type PseudoClassStringArg = Box<str>;
 /// A non tree-structural pseudo-class.
 /// See https://drafts.csswg.org/selectors-4/#structural-pseudos
 #[derive(Clone, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 #[allow(missing_docs)]
 pub enum NonTSPseudoClass {
     Active,
@@ -368,7 +368,7 @@ impl NonTSPseudoClass {
 /// The abstract struct we implement the selector parser implementation on top
 /// of.
 #[derive(Clone, Debug, PartialEq)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct SelectorImpl;
 
 impl ::selectors::SelectorImpl for SelectorImpl {
@@ -601,7 +601,7 @@ impl DerefMut for SnapshotMap {
 
 /// Servo's version of an element snapshot.
 #[derive(Debug)]
-#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct ServoElementSnapshot {
     /// The stored state of the element.
     pub state: Option<ElementState>,

components/style/servo/url.rs

@@ -22,7 +22,7 @@ use values::computed::{Context, ToComputedValue, ComputedUrl};
 ///
 /// However, this approach is still not necessarily optimal: See
 /// <https://bugzilla.mozilla.org/show_bug.cgi?id=1347435#c6>
-#[derive(Clone, Debug, Deserialize, HeapSizeOf, Serialize)]
+#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize)]
 pub struct SpecifiedUrl {
     /// The original URI. This might be optional since we may insert computed
     /// values of images into the cascade directly, and we don't bother to
@@ -30,6 +30,7 @@ pub struct SpecifiedUrl {
     ///
     /// Refcounted since cloning this should be cheap and data: uris can be
     /// really large.
+    #[ignore_malloc_size_of = "Arc"]
     original: Option<Arc<String>>,
 
     /// The resolved value for the url, if valid.