Reexamine out-of-memory tests which are crashing on iOS

[kenrussell]

Per a recent WebGL working group face-to-face meeting, some out-of-memory WebGL conformance tests are crashing the browser on iOS, which is expected behavior as they're allocating more memory than the system allows per process. These tests should be identified, reexamined, and modified to be rigorous but not stress tests.

[kenrussell]

From WebGL F2F 2019/09/25: it looks like this bug may have been referencing extra/out-of-memory.html , which is already a stress test and not part of the conformance suite. @grorg could you please confirm this and close it if so?

[kenrussell]

While investigating WebGL 2.0 support on low-end Android devices in Chromium bug http://crbug.com/1042214 , I found several WebGL conformance tests that allocate so much memory or GPU resources that the Android system kills the entire browser process. This is probably similar to the behavior @grorg saw on iOS. In the list which follows, if there's no comment, it means the operating system killed the web browser. The problematic tests were:

• conformance/rendering/multisample-corruption.html - run within the harness along with other tests, crashes the browser, but passes when run individually (is very slow though)
• conformance/textures/misc/texture-size.html
• deqp/data/gles3/shaders/conversions.html raised a warning "this page is using too much memory, so Chrome removed some content"
• deqp/functional/gles3/texturefiltering/3d_sizes_04.html timed out
• conformance2/misc/uninitialized-test-2.html - renderer (?) process hung while running it
• conformance2/state/gl-object-get-calls.html is very slow
• conformance2/textures/canvas_sub_rectangle/ tests: browser crashed once running these immediately after the conformance2/textures/canvas tests
• conformance2/textures/webgl_canvas/tex-2d-rgb16f-rgb-float.html was very slow
• conformance2/textures/webgl_canvas/tex-2d-rgb32f-rgb-float.html
• conformance2/textures/webgl_canvas/tex-2d-rgba32f-rgba-float.html

I'll look into reducing the memory and/or resource requirements of these tests.