Suppresses a heapchecker leak in base::PlatformThread::SetName().

tools/heapcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 1478 matching lines @@
 }
 {
    bug_65940_b
    Heapcheck:Leak
    fun:__gnu_cxx::new_allocator::allocate
    fun:std::_Vector_base::_M_allocate
    fun:std::vector::_M_insert_aux
    fun:std::vector::push_back
    fun:IPC::ChannelProxy::Context::OnAddFilter
 }
+{
+   bug_136936
+   Heapcheck:Leak
+   ...
+   fun:std::basic_string::_Rep::_S_create
+   ...
+   fun:base::PlatformThread::SetName
+}