fix canvas vs text paint order in Blink/Webkit

* Use Skia to determine "actual" font name.

This way, we don't need to hard-code a mapping of Flutter names
to actual names, we can compute it when the font is registered.

* Refactor to only have loaded and unloaded fonts

This shouldn't result in any logical changes. I've done a quick smoke
test by building a local Android engine and running Flutter gallery, no
compile errors or other obvious issues.

Applied by running `/ci/format.sh | patch -p0` with the altered script
added in flutter/engine#16500. I did locally modify the script slightly
further so it would run against all Java files in the repo instead of
just modified ones.

Uses google-java-format, a tool that's already in place in
flutter/plugins. This should take care of minor style guide issues and
unresolved imports.

Imported from @Rusino's branch

* Modifies accessibility bridge to populate new node fields in semantics API.

* Adds additional UTs and fixes logic for breaking up updates for nodes with large values.

* Chaged tests to set node flags using bitwise-or instead of addition.

* Address bug in update size arithmetic.

* Fixes issue in TruncatesLargeValue unit test causing unexpected deletes.

* Fixes expected number of updates in BatchesLargeMessages unit test to reflect expected values now that node states are populated.

android.os.Parcelable was added in commit
6d5aaa09 but never used.

Make sure that a text range at the end of the string is still valid.

We now have one mutex guarding all accesses to
the underlying task heaps. This simplifies the more granular
but bug prone mechanism of having striped locks.

This also re-enables GPUThreadMerger tests that are currently
disabled due to their flaky nature. The scenario that gets fixed by this
change is as follows:

1. Thread-1: We lock `queue_meta_mutex_` and grab locks on `queue_1` and release the meta mutex.
2. Thread-1: We add an Observer on `queues` object.
3. Thread-2: We lock `queue_meta_mutex_` and grab locks on `queue_2`.
4. Thread-2: We try to dispose all the pending tasks on `queue_2` which calls `erase` on `queues`.

The above situation is not thread safe without having 1 lock.

Note: This increases the contention on one lock and could potentially be bad for perf. We are
explicitly making this trade-off towards reducing the complexity.

Fixes: https://github.com/flutter/flutter/issues/49007

* Ensure fields of Rect and OffsetBase classes are optimized as non-null.

* Update web_ui and formatting