gdb backtrace for a chromium hangup

(gdb) bt
#0  pthread_cond_timedwait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S:238
#1  0x00007f9d69721343 in base::ConditionVariable::TimedWait (this=0x7fffdb12b308, max_time=...)
    at ../../base/synchronization/condition_variable_posix.cc:102
#2  0x00007f9d696fde2c in base::WaitableEvent::TimedWait (this=0x7f9d705c0540, max_time=...)
    at ../../base/synchronization/waitable_event_posix.cc:214
#3  0x00007f9d696dcc16 in base::MessagePumpDefault::Run (this=0x7f9d705c0530, delegate=0x7fffdb12b570)
    at ../../base/message_loop/message_pump_default.cc:56
#4  0x00007f9d696edc51 in base::RunLoop::Run (this=0x7fffdb12b3e0) at ../../base/run_loop.cc:49
#5  0x00007f9d696da157 in base::MessageLoop::Run (this=) at ../../base/message_loop/message_loop.cc:308
#6  0x00007f9d6c310ffc in content::RendererMain (parameters=...) at ../../content/renderer/renderer_main.cc:227
#7  0x00007f9d696a31de in content::RunZygote (main_function_params=..., delegate=)
    at ../../content/app/content_main_runner.cc:339
#8  0x00007f9d696a4071 in content::ContentMainRunnerImpl::Run (this=0x7f9d7059a270)
    at ../../content/app/content_main_runner.cc:764
#9  0x00007f9d696a2db0 in content::ContentMain (params=...) at ../../content/app/content_main.cc:19
#10 0x00007f9d69101ec8 in ChromeMain (argc=4, argv=0x7fffdb12bbd8) at ../../chrome/app/chrome_main.cc:57
#11 0x00007f9d60e91b45 in __libc_start_main (main=0x7f9d69101e70 , argc=4, argv=0x7fffdb12bbd8, 
    init=, fini=, rtld_fini=, stack_end=0x7fffdb12bbc8) at libc-start.c:287
#12 0x00007f9d69101d6f in _start ()
(gdb)