+++ This bug was initially created as a clone of Bug #1041695 +++ Bug 1041695 fixed a crash running the test test_streams_element_capture.html, but it's still failing on Holly and can be reproduced in a local build. The crash is now at child process shutdown and in the code added by bug 1041695: bool ShadowLayerForwarder::InWorkerThread() { return GetMessageLoop()->id() == MessageLoop::current()->id(); } MessageLoop::current() is returning null. A quick hack to short-circuit that and return true when current() returns null then crashes in AssertWorkerThread in MessageChannel.h, which also calls MessageLoop::current(). Short-circuiting *that* then gets the test passing. But I doubt that's correct :) % mach mochitest-plain content/media/test/test_streams_element_capture.html --e10s Stack: > xul.dll!MessageLoop::id() Line 228 + 0xa bytes C++ xul.dll!mozilla::layers::ShadowLayerForwarder::InWorkerThread() Line 490 + 0x22 bytes C++ xul.dll!mozilla::layers::ShadowLayerForwarder::RemoveTexture(mozilla::layers::TextureClient * aTexture) Line 506 + 0x8 bytes C++ xul.dll!mozilla::layers::TextureClient::Finalize() Line 502 C++ xul.dll!mozilla::AtomicRefCountedWithFinalize<mozilla::layers::TextureClient>::Release() Line 61 C++ xul.dll!mozilla::RefPtr<mozilla::layers::TextureClient>::unref(mozilla::layers::TextureClient * aVal) Line 303 C++ xul.dll!mozilla::RefPtr<mozilla::layers::TextureClient>::~RefPtr<mozilla::layers::TextureClient>() Line 242 + 0x12 bytes C++ xul.dll!mozilla::layers::D3D9SurfaceImage::~D3D9SurfaceImage() Line 20 + 0x25 bytes C++ xul.dll!mozilla::layers::D3D9SurfaceImage::`scalar deleting destructor'() + 0xf bytes C++ xul.dll!mozilla::layers::Image::Release() Line 144 + 0x9d bytes C++ xul.dll!nsRefPtr<mozilla::layers::Image>::~nsRefPtr<mozilla::layers::Image>() Line 854 C++ xul.dll!mozilla::VideoFrame::~VideoFrame() Line 26 + 0xf bytes C++ xul.dll!mozilla::VideoChunk::~VideoChunk() Line 91 + 0x12 bytes C++ xul.dll!mozilla::VideoChunk::`scalar deleting destructor'() + 0xf bytes C++ xul.dll!nsTArrayElementTraits<mozilla::VideoChunk>::Destruct(mozilla::VideoChunk * aE) Line 486 + 0xd bytes C++ xul.dll!nsTArray_Impl<mozilla::VideoChunk,nsTArrayInfallibleAllocator>::DestructRange(unsigned int aStart, unsigned int aCount) Line 1642 + 0x9 bytes C++ xul.dll!nsTArray_Impl<mozilla::VideoChunk,nsTArrayInfallibleAllocator>::RemoveElementsAt(unsigned int aStart, unsigned int aCount) Line 1340 C++ xul.dll!mozilla::MediaSegmentBase<mozilla::VideoSegment,mozilla::VideoChunk>::RemoveLeading(__int64 aDuration, unsigned int aStartIndex) Line 350 C++ xul.dll!mozilla::MediaSegmentBase<mozilla::VideoSegment,mozilla::VideoChunk>::ForgetUpTo(__int64 aDuration) Line 170 C++ xul.dll!mozilla::StreamBuffer::Track::ForgetUpTo(__int64 aTime) Line 156 C++ xul.dll!mozilla::StreamBuffer::ForgetUpTo(__int64 aTime) Line 101 C++ xul.dll!mozilla::MediaStream::AdvanceTimeVaryingValuesToCurrentTime(__int64 aCurrentTime, __int64 aBlockedTime) Line 567 C++ xul.dll!mozilla::MediaStreamGraphImpl::UpdateCurrentTimeForStreams(__int64 aPrevCurrentTime, __int64 aNextCurrentTime) Line 399 C++ xul.dll!mozilla::MediaStreamGraphImpl::OneIteration(__int64 aFrom, __int64 aTo, __int64 aStateFrom, __int64 aStateEnd) Line 1407 C++ xul.dll!mozilla::AudioCallbackDriver::DataCallback(float * aBuffer, long aFrames) Line 828 + 0x37 bytes C++ xul.dll!mozilla::AudioCallbackDriver::DataCallback_s(cubeb_stream * aStream, void * aUser, void * aBuffer, long aFrames) Line 717 C++ gkmedias.dll!noop_resampler::fill(void * buffer, long frames_needed) Line 89 + 0x1e bytes C++ gkmedias.dll!cubeb_resampler_fill(cubeb_resampler * resampler, void * buffer, long frames_needed) Line 245 C++ gkmedias.dll!`anonymous namespace'::refill(cubeb_stream * stm, float * data, long frames_needed) Line 239 + 0x14 bytes C++ gkmedias.dll!`anonymous namespace'::wasapi_stream_render_loop(void * stream) Line 332 + 0x11 bytes C++ msvcr100.dll!__endthreadex() + 0x3a bytes msvcr100.dll!__endthreadex() + 0xe4 bytes kernel32.dll!@BaseThreadInitThunk@12() + 0x12 bytes ntdll.dll!___RtlUserThreadStart@8() + 0x27 bytes ntdll.dll!__RtlUserThreadStart@8() + 0x1b bytes

FTR, I disabled test_streams_element_capture.html under e10s on windows in bug 1072739 - it would be great if the patch for this bug can re-enable that test.

A minor fix... This had caused a crash in the test_streams_element_capture mochitest on Windows. The issue was that the audio decoder thread was destroying stale media frames by releasing a reference to them. This was causing the release of an Image on that thread, but that thread does not process a MessageLoop so the current MessageLoop is null. This is not a problem. Obviously, any thread that has no MessageLoop can't be the worker thread.

Try build: https://treeherder.mozilla.org/ui/#/jobs?repo=try&revision=58a45d9c64da Also, this patch does enable (and pass) the test that markh mentioned in comment 1.

Backed out under suspicion that it broke content process leak checking. I'm CCing mccr8 to this bug so you can discuss. https://hg.mozilla.org/integration/mozilla-inbound/rev/f2409cd604c4

I relanded this because it seems like the failure showed up on the prior push as well. https://hg.mozilla.org/integration/mozilla-inbound/rev/450728938eb2