[WIP]Fix OpenGL leak on Android and iOS

[linroid]

Fix flutter/flutter#89658

Both destructors of AndroidContext and IOSContextGL are called on the platform thread, which is a wrong thread to release OpenGL resources.

Instead, this PR calls GrDirectContext::releaseResourcesAndAbandonContext() explictly on rasiterizer task running.

I'm working on investigating a property solution and adding tests.

Related PRs

• Share Android surface GrDirectContext #23798
• implemented GetMainContext() for opengl #23634

Pre-launch Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I read and followed the [Flutter Style Guide] and the [C++, Objective-C, Java style guides].
• I listed at least one issue that this PR fixes in the description above.
• I added new tests to check the change I am making or feature I am adding, or Hixie said the PR is test-exempt. See [testing the engine] for instructions on
  writing and running engine tests.
• I updated/added relevant documentation (doc comments with ///).
• I signed the [CLA].
• All existing and new tests are passing.

[flutter-dashboard]

It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption to this rule, contact Hixie on the #hackers channel in Chat.

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing.

[linroid]

cc @xster @gaaclarke for visibility

[jason-simmons]

See flutter/flutter#87937 (comment)

The engine should not be calling GrDirectContext::releaseResourcesAndAbandonContext on the platform thread (which does not have an EGL context).

This PR is not building though - there is no GPUSurfaceGL constructor that takes a GrDirectContext and a bool.

If the goal is to have AndroidSurfaceGL::CreateGPUSurface return a GPUSurfaceGL with context_owner_ = true when calling SetMainSkiaContext, then I do not think that will be safe if that main_skia_context may later be shared by other GPUSurfaceGL instances.

[linroid]

@jason-simmons I agree that the change is not safe, what about calling GrDirectContext::releaseResourcesAndAbandonContext() on the rasterizer thread when destructing Shell?

[linroid]

@jason-simmons I agree that the change is not safe, what about calling GrDirectContext::releaseResourcesAndAbandonContext() on the rasterizer thread when destructing Shell?

@jason-simmons I have updated my PR with this solution, what do you think? If the solution is ok, I'll patch some tests.

[jason-simmons]

The issue is that the graphics context sharing mechanism allows multiple Shell instances to use the same GrDirectContext. So it will be unsafe for the shell's shutdown process to call releaseResourcesAndAbandonContext if some other shell may still be using the shared GrDirectContext.

[zanderso]

I believe this PR has been made obsolete by some work that @gaaclarke has in progress. Please feel free to re-open if I am mistaken.