GitLab

Add mutex annotations to replace load-bearing comments in
SoftwareImageDecodeCache. This requires adding the proper annotation to
Lock::AssertAcquired(), which is also done in this CL. As a consequence, this CL
does a few things:

In SoftwareImageDecodeCache:
- Convert comments to annotations
- Make a member const instead of annotating it
- Change a test-only method to make compile-time checks pass
- Fix "git cl lint" warnings (include what you use)

In Lock:
- Add a mutex annotation to Lock::AssertAcquired()

Bug: 1013082, 831825, 983348
Change-Id: If779a0f6453a2060ed3e7dedf7ad7f6823ebac68
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1939749
Commit-Queue: Benoit L <lizeb@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Reviewed-by: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720164}