std::_Mutex system leak in std::basic_streambuf on Windows

_From [rnk@google.com](https://code.google.com/u/rnk@google.com/) on April 04, 2012 18:58:14_

We have a bunch of reports like this:

10:51:44 drmemory_analyze.py [INFO] Report `#2`
LEAK 32 direct bytes 0x18619030-0x18619050 + 0 indirect bytes
#0 ntdll.dll!RtlRunOnceBeginInitialize
#1 ntdll.dll!RtlInitializeCriticalSection
#2 _Mtxinit [f:\dd\vctools\crt_bld\self_x86\crt\src\xmtx.c:30]
#3 std::_Mutex::_Mutex [f:\dd\vctools\crt_bld\self_x86\crt\src\xmutex.cpp:13]
#4 std::basic_streambuf >::basic_streambuf > [c:\program files (x86)\microsoft visual studio 9.0\vc\include\streambuf:28]
#5 std::basic_stringbuf,std::allocator >::basic_stringbuf,std::allocator > [c:\program files (x86)\microsoft visual studio 9.0\vc\include\sstream:29]
#6 std::basic_ostringstream,std::allocator >::basic_ostringstream,std::allocator > [c:\program files (x86)\microsoft visual studio 9.0\vc\include\sstream:420]
#7 logging::LogMessage::LogMessage [base\logging.cc:538]
#8 browser_sync::SyncBackendRegistrar::ConfigureDataTypes [chrome\browser\sync\glue\sync_backend_registrar.cc:120]
#9 browser_sync::SyncBackendHost::ConfigureDataTypes [chrome\browser\sync\glue\sync_backend_host.cc:556]
#10 browser_sync::DataTypeManagerImpl::Restart [chrome\browser\sync\glue\data_type_manager_impl.cc:245]
#11 browser_sync::DataTypeManagerImpl::ConfigureImpl [chrome\browser\sync\glue\data_type_manager_impl.cc:199]
#12 browser_sync::DataTypeManagerImpl::Configure [chrome\browser\sync\glue\data_type_manager_impl.cc:125]
#13 ProfileSyncService::ConfigureDataTypeManager [chrome\browser\sync\profile_sync_service.cc:1181]
#14 ProfileSyncService::OnBackendInitialized [chrome\browser\sync\profile_sync_service.cc:661]
#15 TestProfileSyncService::OnBackendInitialized [chrome\browser\sync\test_profile_sync_service.cc:190]
#16 browser_sync::SyncBackendHost::HandleInitializationCompletedOnFrontendLoop [chrome\browser\sync\glue\sync_backend_host.cc:1285]
#17 base::internal::RunnableAdapter const &,bool)>::Run [base\bind_internal.h:246]
Suppression (error hash=#336A11AF6F2BC7A3#):

I don't think there's anything Chrome-specific about this leak, so I'm filing it here. So far as I can tell these LogMessage objects are being cleaned up or we'd be getting reports for them.

_Original issue: http://code.google.com/p/drmemory/issues/detail?id=857_