Leaks found in PrefValueStoreTest tests

tools/valgrind/memcheck/suppressions.txt

Index: tools/valgrind/memcheck/suppressions.txt
diff --git a/tools/valgrind/memcheck/suppressions.txt b/tools/valgrind/memcheck/suppressions.txt
index f08b946c5f9b4cf7cabd5b3dd69cc513345aa7cc..76f1dc5dfac8891087550dc8dc75e489d88dca78 100644
--- a/tools/valgrind/memcheck/suppressions.txt
+++ b/tools/valgrind/memcheck/suppressions.txt
@@ -3898,3 +3898,21 @@
    fun:_ZN9SingletonIN8chromeos12CrosSettingsE22DefaultSingletonTraitsIS1_ES1_E3getEv
    fun:_ZN8chromeos12CrosSettings3GetEv
 }
+{
+   bug_51176_a
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN51PrefValueStoreTest_TestConcurrentPolicyRefresh_Test8TestBodyEv
+}
+{
+   bug_51176_b
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN41PrefValueStoreTest_TestPolicyRefresh_Test8TestBodyEv
+}
+{
+   bug_51176_c
+   Memcheck:Leak
+   fun:_Znw*
+   fun:_ZN56PrefValueStoreTest_TestRefreshPolicyPrefsCompletion_Test8TestBodyEv
+}