GitLab

Both Pipeline and RendererImpl use it's own lock. We could end up with a dead
lock in the following scenario:
- On main thread, Pipeline holds it's lock (lock A) and calls into RendererImpl,
  which also requires the RendererImpl's lock (lock B).
- On media thread, RendererImpl holds it's lock B and calls callback provided by
  the Pipeline, which requires lock A.

This CL makes sure Pipeline never calls into RendererImpl while holding lock A
and RendererImpl nevers calls (back) into Pipeline while holding lock B. So
deadlock should not happen.

This CL also reverts 3 CLs that disabled various tests due to the bug:
- Revert "Exclude tests that deadlock under DrMemory (and Tsan)"
   This reverts commit 0e014b9a.
- Revert "Disable deadlock-y tests in TSan instead of just suppressing the error."
   This reverts commit f712d106.
- Revert "Suppress a deadlock report through media::Pipeline::GetMediaTime."
   This reverts commit 5c72e0f6.

BUG=407452
TEST=Ran PipelineIntegrationTest.ChunkDemuxerAbortRead_VideoOnly in a TSAN build for 10 mins and didn't see any issue.

Review URL: https://codereview.chromium.org/512973002

Cr-Commit-Position: refs/heads/master@{#292332}