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`.

1 files changed, 1 insertions, 3 deletions

diff --git a/components/style/invalidation/element/restyle_hints.rs b/components/style/invalidation/element/restyle_hints.rs
index 94bab930732..06549e4fb0f 100644
--- a/components/style/invalidation/element/restyle_hints.rs
+++ b/components/style/invalidation/element/restyle_hints.rs
@@ -230,9 +230,7 @@ impl From<nsRestyleHint> for RestyleHint {
 }
 
 #[cfg(feature = "servo")]
-impl ::heapsize::HeapSizeOf for RestyleHint {
-    fn heap_size_of_children(&self) -> usize { 0 }
-}
+malloc_size_of_is_0!(RestyleHint);
 
 /// Asserts that all replacement hints have a matching nsRestyleHint value.
 #[cfg(feature = "gecko")]