Break the association between pipelines and browsing context actors.
Now there is one browsing context actor per actual browsing context,
and individual actors keep track of known pipelines as necessary.
There is also one console/performance/timeline/inspector/etc. actor
per browsing context.
This also centralizes more information in the browsing context actor.
Rather than duplicating state for the active pipeline in actors that
need to use it, each actor now remembers the name of its associated
browsing context actor and obtains that state whenever it's necessary.
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`.
* Add support for clip masks on text runs.
* Fix atomic ordering of items with multiple shadows.
* Update to bincode + ipc-channel with optimizations.
* Fix some plane splitting precision errors.
* Improve the anti-aliasing quality significantly.
* Add internal ClipChain support.
* Fix diacritic glyphs on Linux.
