I've just removed "bugs" with ids 52 ("ES3 MSAA is broken on Qualcomm") and 175 ("Adreno 5xx support for EXT_multisampled_render_to_texture is buggy on Android < 7.0") from gpu/config/gpu_driver_bug_list_json.cc and MSAA seems to works just fine on S7 w/Adreno 530/SD 820. 

Hello

Thanks for reporting the issue. Issue is reproducible on Samsung Galaxy S7(SM-G930P)/MMB29M, Chrome: 53.0.2785.124 but does not repro on Samsung Galaxy S7(SM-G930F)/MMB29k, Chrome: 53.0.2785.124.

Logcat & screenshot @ http://go/chrome-androidlogs1/6/655432

Yeah, G930F is Exynos / Mali based, unlike G930P, A, T, and V which are Qualcomm Snapdragon / Adreno based. Same is applicable to S7 Edge (G935F vs G935A,T, P, V).

Victor, can we try these examples on your phone?

artem.bolgar@: thanks for your feedback.

Bug ID 52, https://chromium.googlesource.com/chromium/src/+/master/gpu/config/gpu_driver_bug_list_json.cc#421 , is so old it doesn't even have a bug ID associated. We should conditionalize it to only older Android versions and see if any problems are reported.

Bug ID 175, https://chromium.googlesource.com/chromium/src/+/master/gpu/config/gpu_driver_bug_list_json.cc#1822 , was added for problems seen on the Nexus 6, we believe. Unfortunately since the S7 is still running 6.0 this entry is still hit. We could conditionalize it to driver versions less than 145.0, but that may be risky without more testing.

For more history of these workaround entries see  Issue 449116 ,  Issue 471200 , and Issue 612474.

Re-enabling these code paths without knowing that the associated driver bugs have been fixed can cause incorrect web page rendering on a large population of devices.

Entry 175 was added here:
https://codereview.chromium.org/2176703002/

for good reason -- the associated drivers had known multisampling bugs. Unfortunately, the Samsung S7 hasn't been upgraded to 7.0 and is still running the old affected driver.

I don't think it is worth the risk of destabilizing all of Chrome in order to enable antialiasing for WebGL on this device. I suggest pressuring Samsung to upgrade these devices to Android 7.0 and the latest Qualcomm drivers, which will automatically enable antialiasing.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/e30c559ab432ea328b5eacc3ed09be737ee38641

commit e30c559ab432ea328b5eacc3ed09be737ee38641
Author: kbr <kbr@chromium.org>
Date: Tue Oct 25 22:34:50 2016

Better document ES3 MSAA driver bug workaround for Qualcomm GPUs.

BUG= 449116 ,  471200 , 612474,  655432 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2447233003
Cr-Commit-Position: refs/heads/master@{#427512}

[modify] https://crrev.com/e30c559ab432ea328b5eacc3ed09be737ee38641/gpu/config/gpu_driver_bug_list_json.cc

After reviewing the bugs above which motivated adding these blacklist entries, I think it's too risky to conditionalize them further or remove them.

I suggest pushing Samsung to update the Android version on the S7; if they upgrade it to 7.0 then antialiasing will be available because the GL_EXT_multisampled_render_to_texture extension will stop being disabled.

Closing as WontFix.