Move tsan suppression for SequencedWorkerPool to benign section

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 9ab18007b5743c7cc47e3ac3aefa4cbf5f181a90..f6b62b7666b093d452cbe4f15deac3845025ab97 100644
--- a/tools/valgrind/tsan/suppressions.txt
+++ b/tools/valgrind/tsan/suppressions.txt
@@ -402,6 +402,23 @@
    fun:base::*Histogram::FactoryGet
 }
 
+{
+   bug_115987a [benign races in Histogram in SequencedWorkerPool]
+   ThreadSanitizer:Race
+   ...
+   fun:base::Histogram::*
+   fun:base::SequencedWorkerPool::*
+}
+
+# Histogram macros involve string comparison in debug mode.
+{
+   bug_115987b [benign races in Histogram in SequencedWorkerPool]
+   ThreadSanitizer:Race
+   ...
+   fun:std::operator==
+   fun:base::SequencedWorkerPool::*
+}
+
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 ############################
 # Real races in Chromium
@@ -858,11 +875,4 @@
   fun:AudioRendererHost::OnCreated
   fun:media::AudioOutputController::DoCreate
 }
-{
-   bug_115987
-   ThreadSanitizer:Race
-   ...
-   fun:base::Histogram::Add
-   fun:base::SequencedWorkerPool::Inner::GetWork
-   fun:base::SequencedWorkerPool::Inner::ThreadLoop
-}
+