Add a couple of suppressions to make the MFYI waterfall greener

tools/valgrind/tsan/suppressions.txt

Index: tools/valgrind/tsan/suppressions.txt
diff --git a/tools/valgrind/tsan/suppressions.txt b/tools/valgrind/tsan/suppressions.txt
index 57c536f25f4e12dee3800e1a252bbb3270b49bcc..87ee29478cc87caa19f931ddbd6d76424d2bd10c 100644
--- a/tools/valgrind/tsan/suppressions.txt
+++ b/tools/valgrind/tsan/suppressions.txt
@@ -1031,7 +1031,7 @@
   fun:base::internal::RunnableAdapter::Run
 }
 {
-  bug_344704
+  bug_344704_a
   ThreadSanitizer:Race
   fun:base::Thread::message_loop
   fun:printing::PrintJob::UpdatePrintedDocument
@@ -1040,6 +1040,17 @@
   fun:PrintJobTest_SimplePrint_Test::TestBody
 }
 {
+  bug_344704_b
+  ThreadSanitizer:Race
+  fun:scoped_refptr::operator=
+  fun:base::MessageLoop::~MessageLoop
+  fun:base::MessageLoop::~MessageLoop
+  fun:base::DefaultDeleter::operator()
+  fun:base::internal::scoped_ptr_impl::~scoped_ptr_impl
+  fun:scoped_ptr::~scoped_ptr
+  fun:base::Thread::ThreadMain
+}
+{
   bug_350982
   ThreadSanitizer:Race
   fun:change_state