The Chrome GPU team has deployed a physical Mac bot running ASAN builds in order to try to catch memory corruption errors earlier. Intermittently, running the WebGL 2.0 conformance tests, the following assertion is seen:

# Fatal error in ../../v8/src/heap/spaces.h, line 2471
# Check failed: allocated <= Size() (16507368 vs. 16498664).
#

==== C stack trace ===============================

0 Chromium Framework 0x000000010e078f93 v8::base::debug::StackTrace::StackTrace() + 19
1 Chromium Framework 0x000000010e073667 V8_Fatal + 423
2 Chromium Framework 0x0000000104f5f172 v8::internal::NewSpace::AllocatedSinceLastGC() + 1570
3 Chromium Framework 0x0000000104f5548d v8::internal::GCTracer::Start(v8::internal::GarbageCollector, v8::internal::GarbageCollectionReason, char const*) + 765
4 Chromium Framework 0x0000000104f6df36 v8::internal::Heap::CollectGarbage(v8::internal::GarbageCollector, v8::internal::GarbageCollectionReason, char const*, v8::GCCallbackFlags) + 1622
5 Chromium Framework 0x0000000104ea35f6 v8::internal::Factory::NewFillerObject(int, bool, v8::internal::AllocationSpace) + 310
6 Chromium Framework 0x000000010575032c v8::internal::__RT_impl_Runtime_AllocateInTargetSpace(v8::internal::Arguments, v8::internal::Isolate*) + 460
7 Chromium Framework 0x000000010574f936 v8::internal::Runtime_AllocateInTargetSpace(int, v8::internal::Object**, v8::internal::Isolate*) + 694
8 ??? 0x000000012840e58d 0x0 + 4970309005


This affected the following two builds:

https://build.chromium.org/p/chromium.gpu.fyi/builders/Mac%20GPU%20ASAN%20Release/builds/881
 - WebglConformance_deqp_functional_gles3_texturespecification_texstorage2d_format_2d_01
 - https://chromium-swarm.appspot.com/task?id=32f83ea865811410&refresh=10&show_raw=1

https://build.chromium.org/p/chromium.gpu.fyi/builders/Mac%20GPU%20ASAN%20Release/builds/882
 - WebglConformance_deqp_functional_gles3_framebufferblit_default_framebuffer_01
 - https://chromium-swarm.appspot.com/task?id=32f8f279f5634310&refresh=10&show_raw=1


V8 GC folks, could you please look into this? It isn't the highest priority, but it would be great if we could get this bot reliably green. It could catch a significant class of memory errors in Chrome's graphics stack.

Thanks.