The webkit test output is missing the crash stack:

https://storage.googleapis.com/chromium-layout-test-archives/mac_chromium_rel_ng/260599/layout-test-results/results.html

The crash is in the main log:
https://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_ng/builds/260599/steps/webkit_tests%20%28with%20patch%29/logs/stdio

20:12:13.472 10761 worker/0 fast/events/popup-allowed-from-gesture-initiated-form-submit.html output stderr lines:
20:12:13.472 10761   [11625:1287:0714/201207:1872661282814:FATAL:navigation_controller_impl.cc(673)] Check failed: false. Http post load must use http(s) scheme.
20:12:13.472 10761   0   Content Shell Framework             0x000000010b99c1a3 _ZN4base5debug10StackTraceC1Ev + 19
20:12:13.472 10761   1   Content Shell Framework             0x000000010b9bc917 _ZN7logging10LogMessageD2Ev + 71
20:12:13.472 10761   2   Content Shell Framework             0x000000010b2906f1 _ZN7content24NavigationControllerImpl17LoadURLWithParamsERKNS_20NavigationController13LoadURLParamsE + 417
20:12:13.472 10761   3   Content Shell Framework             0x000000010b7898ba _ZN7content5Shell14OpenURLFromTabEPNS_11WebContentsERKNS_13OpenURLParamsE + 378
20:12:13.472 10761   4   Content Shell Framework             0x000000010b5ade8c _ZN7content15WebContentsImpl14RequestOpenURLEPNS_19RenderFrameHostImplERKNS_13OpenURLParamsE + 76
20:12:13.472 10761   5   Content Shell Framework             0x000000010b2a0fcf _ZN7content13NavigatorImpl14RequestOpenURLEPNS_19RenderFrameHostImplERK4GURLbRK13scoped_refptrINS_23ResourceRequestBodyImplEEPNS_12SiteInstanceERKNS_8ReferrerE21WindowOpenDispositionbb + 591
20:12:13.472 10761   6   Content Shell Framework             0x000000010b2aefe8 _ZN7content19RenderFrameHostImpl7OpenURLERK27FrameHostMsg_OpenURL_ParamsPNS_12SiteInstanceE + 216
20:12:13.472 10761   7   Content Shell Framework             0x000000010b2a831c _ZN7content19RenderFrameHostImpl9OnOpenURLERK27FrameHostMsg_OpenURL_Params + 156
20:12:13.472 10761   8   Content Shell Framework             0x000000010b2a818e _ZN3IPC8MessageTI25FrameHostMsg_OpenURL_MetaNSt3__15tupleIJ27FrameHostMsg_OpenURL_ParamsEEEvE8DispatchIN7content19RenderFrameHostImplES9_vMS9_FvRKS4_EEEbPKNS_7MessageEPT_PT0_PT1_T2_ + 126
20:12:13.472 10761   9   Content Shell Framework             0x000000010b2a5bf4 _ZN7content19RenderFrameHostImpl17OnMessageReceivedERKN3IPC7MessageE + 2564
20:12:13.472 10761   10  Content Shell Framework             0x000000010b4777de _ZN7content21RenderProcessHostImpl17OnMessageReceivedERKN3IPC7MessageE + 526
20:12:13.473 10761   11  Content Shell Framework             0x000000010ba81888 _ZN3IPC12ChannelProxy7Context17OnDispatchMessageERKNS_7MessageE + 40
20:12:13.473 10761   12  Content Shell Framework             0x000000010b99c81b _ZN4base5debug13TaskAnnotator7RunTaskEPKcRKNS_11PendingTaskE + 187


See build:
https://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_ng/builds/260599