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, 2 insertions, 1 deletions

diff --git a/components/style/servo/url.rs b/components/style/servo/url.rs
index 0169ff9c884..6dc1d46d2aa 100644
--- a/components/style/servo/url.rs
+++ b/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.