Suppress InvalidationClientImpl leaks on Valgrind and Heapcheck

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 # running overnight and removing outdated bugs/suppressions.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 1864 matching lines @@
    fun:net::HostResolverImpl::Job::OnProcTaskComplete
 }
 {
    bug_117995
    Heapcheck:Leak
    fun:std::string::_Rep::_S_create
    fun:std::string::copy
    fun:std::basic_string::basic_string
    fun:chromeos::UserManagerTest_*_Test::TestBody
 }
+{
+   bug_118203
+   Heapcheck:Leak
+   ...
+   fun:invalidation::NewPermanentCallback
+   fun:invalidation::InvalidationClientImpl::ScheduleStartAfterReadingStateBlob
+   fun:invalidation::InvalidationClientImpl::Start
+   fun:sync_notifier::ChromeInvalidationClient::Start
+}