Also see https://bugs.chromium.org/p/chromium/issues/detail?id=657495.

"""
(lldb) process launch -- --user-data-dir=/tmp/a7 --memlog=browser
Process 11600 launched: '/Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary' (x86_64)
[11600:45059:0906/100831.963891:ERROR:service_manager.cc(156)] Connection InterfaceProviderSpec prevented service: content_utility from binding interface: content::mojom::FieldTrialRecorder exposed by: content_browser
AVDCreateGPUAccelerator: Error loading GPU renderer
objc[11600]: __weak variable at 0x109b0d6d0 holds 0x2121212121212121 instead of 0x116900f10. This is probably incorrect use of objc_storeWeak() and objc_loadWeak(). Break on objc_weak_error to debug.

Process 11600 stopped
* thread #38, name = 'Service Discovery Thread', stop reason = breakpoint 1.1
    frame #0: 0x00007fffbb57125a libobjc.A.dylib`objc_weak_error
libobjc.A.dylib`objc_weak_error:
->  0x7fffbb57125a <+0>: retq   

libobjc.A.dylib`bad_weak_table:
    0x7fffbb57125b <+0>: pushq  %rbp
    0x7fffbb57125c <+1>: movq   %rsp, %rbp
    0x7fffbb57125f <+4>: movq   %rdi, %rcx
(lldb) bt
* thread #38, name = 'Service Discovery Thread', stop reason = breakpoint 1.1
  * frame #0: 0x00007fffbb57125a libobjc.A.dylib`objc_weak_error
    frame #1: 0x00007fffbb55fdce libobjc.A.dylib`weak_clear_no_lock + 140
    frame #2: 0x00007fffbb55fcf0 libobjc.A.dylib`objc_object::clearDeallocating_slow() + 104
    frame #3: 0x00007fffbb5595b1 libobjc.A.dylib`objc_destructInstance + 153
    frame #4: 0x00000001045c1f09 Google Chrome Framework`___lldb_unnamed_symbol181540$$Google Chrome Framework + 89
    frame #5: 0x0000000103342e22 Google Chrome Framework`___lldb_unnamed_symbol116002$$Google Chrome Framework + 66
    frame #6: 0x0000000103345e16 Google Chrome Framework`___lldb_unnamed_symbol116047$$Google Chrome Framework + 22
    frame #7: 0x00000001033953b4 Google Chrome Framework`___lldb_unnamed_symbol117700$$Google Chrome Framework + 276
    frame #8: 0x00000001033bb5f4 Google Chrome Framework`___lldb_unnamed_symbol118621$$Google Chrome Framework + 500
    frame #9: 0x00000001033bbcab Google Chrome Framework`___lldb_unnamed_symbol118624$$Google Chrome Framework + 667
    frame #10: 0x00000001033be57a Google Chrome Framework`___lldb_unnamed_symbol118689$$Google Chrome Framework + 42
    frame #11: 0x00000001033af58a Google Chrome Framework`___lldb_unnamed_symbol118244$$Google Chrome Framework + 10
    frame #12: 0x00000001033bde6f Google Chrome Framework`___lldb_unnamed_symbol118677$$Google Chrome Framework + 63
    frame #13: 0x00007fffa61333e1 CoreFoundation`__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
    frame #14: 0x00007fffa611465c CoreFoundation`__CFRunLoopDoSources0 + 556
    frame #15: 0x00007fffa6113b46 CoreFoundation`__CFRunLoopRun + 934
    frame #16: 0x00007fffa6113544 CoreFoundation`CFRunLoopRunSpecific + 420
    frame #17: 0x00007fffa7b44252 Foundation`-[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 277
    frame #18: 0x00000001033bebfe Google Chrome Framework`___lldb_unnamed_symbol118710$$Google Chrome Framework + 126
    frame #19: 0x00000001033bd74c Google Chrome Framework`___lldb_unnamed_symbol118671$$Google Chrome Framework + 92
    frame #20: 0x00000001033e0803 Google Chrome Framework`___lldb_unnamed_symbol119466$$Google Chrome Framework + 51
    frame #21: 0x0000000103411b1b Google Chrome Framework`___lldb_unnamed_symbol120265$$Google Chrome Framework + 395
    frame #22: 0x000000010340c057 Google Chrome Framework`___lldb_unnamed_symbol120156$$Google Chrome Framework + 87
    frame #23: 0x00007fffbc05f93b libsystem_pthread.dylib`_pthread_body + 180
    frame #24: 0x00007fffbc05f887 libsystem_pthread.dylib`_pthread_start + 286
    frame #25: 0x00007fffbc05f08d libsystem_pthread.dylib`thread_start + 13
"""

Sampling the process, then symbolizing:
"""
    2679 Thread_39617552: Service Discovery Thread
    + 2679 thread_start  (in libsystem_pthread.dylib) + 13  [0x7fffbc05f08d]
    +   2679 _pthread_start  (in libsystem_pthread.dylib) + 286  [0x7fffbc05f887]
    +     2679 _pthread_body  (in libsystem_pthread.dylib) + 180  [0x7fffbc05f93b]
    +       2679 base::(anonymous namespace)::ThreadFunc(void*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1c0c057  [platform_thread_posix.cc:77]
    +         2679 base::Thread::ThreadMain()  (in Google Chrome Framework)  load address 0x101800000 + 0x1c11b1b  [lock.h:26]
    +           2679 base::RunLoop::Run()  (in Google Chrome Framework)  load address 0x101800000 + 0x1be0803  [run_loop.cc:124]
    +             2679 base::MessagePumpCFRunLoopBase::Run(base::MessagePump::Delegate*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbd74c  [message_pump_mac.mm:278]
    +               2679 base::MessagePumpNSRunLoop::DoRun(base::MessagePump::Delegate*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbebfe  [message_pump_mac.mm:691]
    +                 2679 -[NSRunLoop(NSRunLoop) runMode:beforeDate:]  (in Foundation) + 277  [0x7fffa7b44252]
    +                   2679 CFRunLoopRunSpecific  (in CoreFoundation) + 420  [0x7fffa6113544]
    +                     2679 __CFRunLoopRun  (in CoreFoundation) + 934  [0x7fffa6113b46]
    +                       2679 __CFRunLoopDoSources0  (in CoreFoundation) + 556  [0x7fffa611465c]
    +                         2679 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__  (in CoreFoundation) + 17  [0x7fffa61333e1]
    +                           2679 base::MessagePumpCFRunLoopBase::RunWorkSource(void*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbde6f  [message_pump_mac.mm:400]
    +                             2679 base::mac::CallWithEHFrame(void () block_pointer)  (in Google Chrome Framework)  load address 0x101800000 + 0x1baf58a  []
    +                               2679 base::MessagePumpCFRunLoopBase::RunWork()  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbe57a  [message_pump_mac.mm:421]
    +                                 2679 base::MessageLoop::DoWork()  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbbcab  [message_loop.cc:524]
    +                                   2679 base::MessageLoop::RunTask(base::PendingTask*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1bbb5f4  [vector:639]
    +                                     2679 base::debug::TaskAnnotator::RunTask(char const*, base::PendingTask*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1b953b4  [callback_forward.h:11]
    +                                       2679 base::DeleteHelper<local_discovery::ServiceWatcherImplMac::NetServiceBrowserContainer>::DoDelete(void const*)  (in Google Chrome Framework)  load address 0x101800000 + 0x1b45e16  [sequenced_task_runner_helpers.h:24]
    +                                         2679 local_discovery::ServiceWatcherImplMac::NetServiceBrowserContainer::~NetServiceBrowserContainer()  (in Google Chrome Framework)  load address 0x101800000 + 0x1b42e22  [ref_counted.h:534]
    +                                           2679 (anonymous namespace)::ZombieDealloc(objc_object*, objc_selector*)  (in Google Chrome Framework)  load address 0x101800000 + 0x2dc1f09  [objc_zombie.mm:118]
    +                                             2679 objc_destructInstance  (in libobjc.A.dylib) + 153  [0x7fffbb5595b1]
    +                                               2679 objc_object::clearDeallocating_slow()  (in libobjc.A.dylib) + 104  [0x7fffbb55fcf0]
    +                                                 2679 weak_clear_no_lock  (in libobjc.A.dylib) + 140  [0x7fffbb55fdce]
    +                                                   2679 objc_weak_error  (in libobjc.A.dylib) + 0  [0x7fffbb57125a]
"""