Bug 187734

The following layout test is Crashing on [High Sierra Debug WK2 and Sierra Debug WK2]

webrtc/video-addTransceiver.html

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x000000012727b61d bmalloc::SmallLine::deref(std::__1::unique_lock<bmalloc::Mutex>&) + 45 (SmallLine.h:62)
1   com.apple.JavaScriptCore      	0x000000012727b35c bmalloc::Heap::derefSmallLine(std::__1::unique_lock<bmalloc::Mutex>&, bmalloc::Object, std::__1::array<bmalloc::List<bmalloc::SmallPage>, 112ul>&) + 60 (Heap.h:175)
2   com.apple.JavaScriptCore      	0x000000012727b285 bmalloc::Deallocator::processObjectLog(std::__1::unique_lock<bmalloc::Mutex>&) + 165 (Deallocator.cpp:69)
3   com.apple.JavaScriptCore      	0x0000000127277be4 bmalloc::Allocator::refillAllocatorSlowCase(bmalloc::BumpAllocator&, unsigned long) + 148 (Allocator.cpp:155)
4   com.apple.JavaScriptCore      	0x0000000127278063 bmalloc::Allocator::allocateSlowCase(unsigned long) + 243 (Allocator.cpp:190)
5   com.apple.JavaScriptCore      	0x00000001271ebc88 bmalloc::Allocator::allocate(unsigned long) + 72 (Allocator.h:91)
6   com.apple.JavaScriptCore      	0x00000001271ebbd6 bmalloc::Cache::allocate(bmalloc::HeapKind, unsigned long) + 166 (Cache.h:79)
7   com.apple.JavaScriptCore      	0x00000001271eb38b bmalloc::api::malloc(unsigned long, bmalloc::HeapKind) + 27 (bmalloc.h:49)
8   com.apple.JavaScriptCore      	0x00000001271eb156 WTF::fastMalloc(unsigned long) + 118 (FastMalloc.cpp:273)
9   com.apple.WebKit              	0x00000001143c0685 WTF::Function<void ()>::CallableWrapperBase::operator new(unsigned long) + 21 (Function.h:83)
10  com.apple.WebKit              	0x00000001144e65af WTF::Function<void ()>::Function<IPC::Connection::sendMessage(std::__1::unique_ptr<IPC::Encoder, std::__1::default_delete<IPC::Encoder> >, WTF::OptionSet<IPC::SendOption>)::$_6, void>(IPC::Connection::sendMessage(std::__1::unique_ptr<IPC::Encoder, std::__1::default_delete<IPC::Encoder> >, WTF::OptionSet<IPC::SendOption>)::$_6&&) + 79 (Function.h:43)
11  com.apple.WebKit              	0x00000001144cfc1d WTF::Function<void ()>::Function<IPC::Connection::sendMessage(std::__1::unique_ptr<IPC::Encoder, std::__1::default_delete<IPC::Encoder> >, WTF::OptionSet<IPC::SendOption>)::$_6, void>(IPC::Connection::sendMessage(std::__1::unique_ptr<IPC::Encoder, std::__1::default_delete<IPC::Encoder> >, WTF::OptionSet<IPC::SendOption>)::$_6&&) + 29 (Function.h:45)
12  com.apple.WebKit              	0x00000001144cf102 IPC::Connection::sendMessage(std::__1::unique_ptr<IPC::Encoder, std::__1::default_delete<IPC::Encoder> >, WTF::OptionSet<IPC::SendOption>) + 2994 (Connection.cpp:405)
13  com.apple.WebKit              	0x00000001145c4ff2 bool IPC::Connection::send<Messages::NetworkRTCSocket::Close>(Messages::NetworkRTCSocket::Close&&, unsigned long long, WTF::OptionSet<IPC::SendOption>) + 994 (Connection.h:402)
14  com.apple.WebKit              	0x00000001145c4bf9 WebKit::LibWebRTCSocket::Close()::$_1::operator()(IPC::Connection&) const + 137 (LibWebRTCSocket.cpp:152)
15  com.apple.WebKit              	0x00000001145c4b44 WTF::Function<void (IPC::Connection&)>::CallableWrapper<WebKit::LibWebRTCSocket::Close()::$_1>::call(IPC::Connection&) + 52 (Function.h:101)
16  com.apple.WebKit              	0x00000001145ba60e WTF::Function<void (IPC::Connection&)>::operator()(IPC::Connection&) const + 158 (Function.h:56)
17  com.apple.WebKit              	0x00000001145c0ea5 WebKit::sendOnMainThread(WTF::Function<void (IPC::Connection&)>&&)::'lambda'()::operator()() const + 53 (LibWebRTCSocket.cpp:47)
18  com.apple.WebKit              	0x00000001145c0de9 WTF::Function<void ()>::CallableWrapper<WebKit::sendOnMainThread(WTF::Function<void (IPC::Connection&)>&&)::'lambda'()>::call() + 25 (Function.h:101)
19  com.apple.JavaScriptCore      	0x00000001271d568b WTF::Function<void ()>::operator()() const + 139 (Function.h:56)
20  com.apple.JavaScriptCore      	0x0000000127201fc4 WTF::dispatchFunctionsFromMainThread() + 324 (MainThread.cpp:129)
21  com.apple.JavaScriptCore      	0x0000000127204c75 -[JSWTFMainThreadCaller call] + 21 (MainThreadMac.mm:55)
22  com.apple.Foundation          	0x00007fff77fb452a __NSThreadPerformPerform + 326
23  com.apple.CoreFoundation      	0x00007fff765543e1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
24  com.apple.CoreFoundation      	0x00007fff7653565c __CFRunLoopDoSources0 + 556
25  com.apple.CoreFoundation      	0x00007fff76534b46 __CFRunLoopRun + 934
26  com.apple.CoreFoundation      	0x00007fff76534544 CFRunLoopRunSpecific + 420
27  com.apple.HIToolbox           	0x00007fff75a93ebc RunCurrentEventLoopInMode + 240
28  com.apple.HIToolbox           	0x00007fff75a93cf1 ReceiveNextEventCommon + 432
29  com.apple.HIToolbox           	0x00007fff75a93b26 _BlockUntilNextEventMatchingListInModeWithFilter + 71
30  com.apple.AppKit              	0x00007fff7402aa54 _DPSNextEvent + 1120
31  com.apple.AppKit              	0x00007fff747a67ee -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] + 2796
32  com.apple.AppKit              	0x00007fff7401f3db -[NSApplication run] + 926
33  com.apple.AppKit              	0x00007fff73fe9e0e NSApplicationMain + 1237
34  libxpc.dylib                  	0x00007fff8c3578c7 _xpc_objc_main + 775
35  libxpc.dylib                  	0x00007fff8c3562e4 xpc_main + 494
36  com.apple.WebKit.WebContent   	0x000000010fc7f0c5 main + 1189 (XPCServiceMain.mm:160)
37  libdyld.dylib                 	0x00007fff8c0fe235 start + 1

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=webrtc%2Fvideo-addTransceiver.html