On debug emulator builds: 15:46:24 INFO - 4619 INFO TEST-START | /tests/dom/workers/test/test_onLine.html 15:46:24 INFO - ############ ErrorPage.js 15:46:24 INFO - [Parent 670] WARNING: RemoveObserver() called for unregistered observer: file ../../gecko/hal/Hal.cpp, line 204 15:46:24 INFO - [Parent 670] WARNING: RemoveObserver() called for unregistered observer: file ../../gecko/hal/Hal.cpp, line 204 15:46:24 INFO - [Parent 670] WARNING: RemoveObserver() called for unregistered observer: file ../../gecko/hal/Hal.cpp, line 204 15:53:54 INFO - [Parent 670] WARNING: RemoveObserver() called for unregistered observer: file ..B2GRunner TEST-UNEXPECTED-FAIL | /tests/dom/workers/test/test_onLine.html | application timed out after 450.0 seconds with no output 15:53:54 INFO - B2GRunner INFO | checking for crashes in '/data/local/tests/profile/minidumps' 15:54:11 INFO - /../gecko/hal/Hal.cpp, line 204 15:54:11 INFO - [Parent 670] WARNING: NS_ENSURE_TRUE(mCallback) failed: file ../../../../gecko/content/base/src/nsFrameMessageManager.cpp, line 641 15:54:11 INFO - ************************************************************ 15:54:11 INFO - * Call to xpconnect wrapped JSObject produced this error: * 15:54:11 INFO - [Exception... "Component returned failure code: 0xc1f30001 (NS_ERROR_NOT_INITIALIZED) [nsIMessageSender.sendAsyncMessage]" nsresult: "0xc1f30001 (NS_ERROR_NOT_INITIALIZED)" location: "JS frame :: chrome://specialpowers/content/SpecialPowersObserver.js :: SpecialPowersObserver.prototype._sendAsyncMessage :: line 89" data: no] 15:54:11 INFO - ************************************************************ 15:54:11 WARNING - PROCESS-CRASH | /tests/dom/workers/test/test_onLine.html | application crashed [@ mozilla::net::HttpChannelChild::Release()] 15:54:11 INFO - Crash dump filename: /tmp/tmp7Q4HJO/109e0f36-db1f-3447-31903853-256eb6a1.dmp 15:54:11 INFO - Operating system: Android 15:54:11 INFO - 0.0.0 Linux 2.6.29-00297-ge2ba18d #4 Tue Sep 24 09:35:47 UTC 2013 armv7l Android/full/generic:4.0.4.0.4.0.4/OPENMASTER/eng.cltbld.20140109.132654:eng/test-keys 15:54:11 INFO - CPU: arm 15:54:11 INFO - 0 CPUs 15:54:11 INFO - Crash reason: SIGSEGV 15:54:11 INFO - Crash address: 0x0 15:54:11 INFO - Thread 14 (crashed) 15:54:11 INFO - 0 libxul.so!mozilla::net::HttpChannelChild::Release() [HttpChannelChild.cpp:af2900e3b1f3 : 65 + 0x4] 15:54:11 INFO - r4 = 0x44e85400 r5 = 0x44e85428 r6 = 0x40222080 r7 = 0x44f69428 15:54:11 INFO - r8 = 0x458fec34 r9 = 0x458fec7c r10 = 0x458fede0 fp = 0x00000001 15:54:11 INFO - sp = 0x458feb38 lr = 0x406df005 pc = 0x406df008 15:54:11 INFO - Found by: given as instruction pointer in context 15:54:11 INFO - 1 libxul.so!mozilla::MediaBufferDecoder::~MediaBufferDecoder [nsCOMPtr.h : 517 + 0x5] 15:54:11 INFO - r4 = 0x458feb6c r5 = 0x00000000 r6 = 0x458fec1c r7 = 0x44f69428 15:54:11 INFO - r8 = 0x458fec34 r9 = 0x458fec7c r10 = 0x458fede0 fp = 0x00000001 15:54:11 INFO - sp = 0x458feb50 pc = 0x4059d7bb 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 2 libxul.so!nsCOMPtr<nsIChannel>::Assert_NoQueryNeeded() [nsCOMPtr.h : 528 + 0x5] 15:54:11 INFO - r4 = 0x458fec34 r5 = 0x00000000 r6 = 0x458fec1c r7 = 0x44f69428 15:54:11 INFO - r8 = 0x458fec34 r9 = 0x458fec7c r10 = 0x458fede0 fp = 0x00000001 15:54:11 INFO - sp = 0x458feb58 pc = 0x4061527b 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 3 libxul.so!mozilla::dom::workers::WorkerPrivate::GetLoadInfo(JSContext*, nsPIDOMWindow*, mozilla::dom::workers::WorkerPrivate*, nsAString_internal const&, bool, mozilla::dom::workers::WorkerPrivateParent<mozilla::dom::workers::WorkerPrivate>::LoadInfo*) [nsCOMPtr.h : 1330 + 0xb] 15:54:11 INFO - r4 = 0x44f0bbd0 r5 = 0x44f69400 r6 = 0x458fec1c r7 = 0x44f69428 15:54:11 INFO - r8 = 0x458fec34 r9 = 0x458fec7c r10 = 0x458fede0 fp = 0x00000001 15:54:11 INFO - sp = 0x458feb80 pc = 0x40fc8349 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 4 libxul.so!mozilla::dom::workers::WorkerPrivate::Constructor(mozilla::dom::GlobalObject const&, nsAString_internal const&, bool, mozilla::dom::workers::WorkerPrivateParent<mozilla::dom::workers::WorkerPrivate>::WorkerType, nsAString_internal const&, mozilla::dom::workers::WorkerPrivateParent<mozilla::dom::workers::WorkerPrivate>::LoadInfo*, mozilla::ErrorResult&) [WorkerPrivate.cpp:af2900e3b1f3 : 3717 + 0x15] 15:54:11 INFO - r4 = 0x458fecf8 r5 = 0x44f69400 r6 = 0x458feda8 r7 = 0x44f0bbd0 15:54:11 INFO - r8 = 0x00000000 r9 = 0x428d1c0c r10 = 0x00000000 fp = 0x458fede0 15:54:11 INFO - sp = 0x458fece0 pc = 0x40fc8ff5 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 5 libxul.so!mozilla::dom::workers::WorkerPrivate::Constructor(mozilla::dom::GlobalObject const&, nsAString_internal const&, mozilla::ErrorResult&) [WorkerPrivate.cpp:af2900e3b1f3 : 3648 + 0x15] 15:54:11 INFO - r4 = 0x458fed8c r5 = 0x458fede0 r6 = 0x458feda8 r7 = 0x458fedd0 15:54:11 INFO - r8 = 0x00000000 r9 = 0x44f91120 r10 = 0x44f0bbd0 fp = 0x47632e00 15:54:11 INFO - sp = 0x458fed58 pc = 0x40fc91a3 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 6 libxul.so!mozilla::dom::WorkerBinding::_constructor [WorkerBinding.cpp : 703 + 0xd] 15:54:11 INFO - r4 = 0x00000000 r5 = 0x458feda8 r6 = 0x00000000 r7 = 0x458fedd0 15:54:11 INFO - r8 = 0x00000000 r9 = 0x44f91120 r10 = 0x44f0bbd0 fp = 0x47632e00 15:54:11 INFO - sp = 0x458fed78 pc = 0x40d06083 15:54:11 INFO - Found by: call frame info 15:54:11 INFO - 7 libxul.so!js::CallJSNative(JSContext*, bool (*)(JSContext*, unsigned int, JS::Value*), JS::CallArgs const&) [jscntxtinlines.h:af2900e3b1f3 : 220 + 0x3] 15:54:11 INFO - r4 = 0x00000000 r5 = 0x44f0bbd0 r6 = 0x458feeb4 r7 = 0x40d05fa5 15:54:11 INFO - r8 = 0x44f91128 r9 = 0x458fee38 r10 = 0x00000000 fp = 0x47632e00 15:54:11 INFO - sp = 0x458fee30 pc = 0x41ca22b1

This is reproducible. I don't think the navigator.onLine patch itself is responsible for this. Investigating a little later.