Attempt 2 at fixing crash in ProcessPendingTabs. This differs from the

chrome/test/data/reliability/known_crashes.txt

 # This file contains known patterns of crash signatures. One pattern per line.
 #
 # A crash signature is the concatenation of the top N functions, delimited by
 # '___', in chrome.dll on the crash stack. All characters are lower case.
 #
 # We use crash signature patterns as our list of known crashes. A crash
 # signature pattern is a string that can be used to identify a known crash. We
 # use the notion of patterns because crashes with the same root cause can often
 # differ somewhat in their crash stacks. A pattern is intended to be a
 # generalized, yet still identifying, form of a particular crash. Usually a
@@ skipping 22 matching lines @@
 # It is too broad to exclude all purecall related crashes. Thus here we filter
 # any purecall crash immediately after runtask.
 SUBSTRING : purecall___messageloop::runtask
 REGEX : purecall___[^_]*___messageloop::runtask
 REGEX : `anonymous namespace'::purecall$
 
 # Ditto for InvalidParameter.  Unfortunately, we see a crash where that call
 # is the only one on the stack, so ignore that instance
 REGEX : `anonymous namespace'::invalidparameter$
 
-# 15620
-PREFIX : browser::processpendingtabs___browser::clearunloadstate
-
 # 47207
 PREFIX : messageloop::runtask___messageloop::deferorrunpendingtask___messageloop::dodelayedwork___base::messagepumpforio::dorunloop___base::messagepumpwin::run___messageloop::runinternal___messageloop::run___base::thread::run___base::thread::threadmain___`anonymous namespace'::threadfunc
 PREFIX : messageloop::runtask___messageloop::dodelayedwork___base::messagepumpforio::dorunloop___base::messagepumpwin::run___messageloop::runinternal___messageloop::run___base::thread::run___base::thread::threadmain___`anonymous namespace'::threadfunc
 
 # 48712
 PREFIX : npapi::plugininstance::npp_newstream
 
 # 49271
 PREFIX : messageloop::posttask_helper___messageloop::posttask___disk_cache::inflightio::oniocomplete___disk_cache::backendio::executebackendoperation___messageloop::runtask___messageloop::dowork___base::messagepumpforio::dorunloop___base::messagepumpwin::run___messageloop::runinternal___messageloop::run___base::thread::run___base::thread::threadmain___`anonymous namespace'::threadfunc
 
@@ skipping 81 matching lines @@
 # (SUBSTRING rather than PREFIX to catch known variants of this issue)
 SUBSTRING : url_canon::canonicalizeipaddress___url_canon::`anonymous namespace'::dohost<wchar_t,wchar_t>___url_canon::canonicalizehost___url_canon::`anonymous namespace'::docanonicalizestandardurl<wchar_t,wchar_t>___url_canon::canonicalizestandardurl___url_util::`anonymous namespace'::docanonicalize<wchar_t>___url_util::`anonymous namespace'::doresolverelative<wchar_t>
 
 # 66795
 PREFIX : webkit_glue::resourcefetcher::didfail___webkit_glue::weburlloaderimpl::context::oncompletedrequest___resourcedispatcher::onrequestcomplete___ipc::messagewithtuple<tuple4<int,urlrequeststatus,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,base::time> >::dispatch<resourcedispatcher,void (__thiscall resourcedispatcher::*)(int,urlrequeststatus const &,std::basic_string<char,std::char_traits<char>,std::allocator<char> > const &,base::time const &)>___resourcedispatcher::dispatchmessagew___resourcedispatcher::onmessagereceived___childthread::onmessagereceived___runnablemethod<selectfiledialogimpl,void (__thiscall selectfiledialogimpl::*)(selectfiledialogimpl::executeselectparams const &),tuple1<selectfiledialogimpl::executeselectparams> >::run___messageloop::runtask___messageloop::dowork___base::messagepumpdefault::run___messageloop::runinternal___messageloop::run___renderermain
 PREFIX : webkit_glue::resourcefetcher::didfail___webkit_glue::weburlloaderimpl::context::oncompletedrequest___resourcedispatcher::onrequestcomplete___ipc::messagewithtuple<tuple4<int,urlrequeststatus,std::basic_string<char,std::char_traits<char>,std::allocator<char> >,base::time> >::dispatch<resourcedispatcher,resourcedispatcher,void (__thiscall resourcedispatcher::*)(int,urlrequeststatus const &,std::basic_string<char,std::char_traits<char>,std::allocator<char> > const &,base::time const &)>___resourcedispatcher::dispatchmessagew___resourcedispatcher::onmessagereceived___childthread::onmessagereceived___runnablemethod<profilewriter,void (__thiscall profilewriter::*)(gurl const &),tuple1<gurl> >::run___messageloop::runtask___messageloop::dowork___base::messagepumpdefault::run___messageloop::runinternal___messageloop::run___renderermain
 
 # 68516
 REGEX: tcmalloc.+webcore.+
 REGEX: `anonymous namespace'::do_free_with_callback.+webcore.+