Suppress all the leaks from ExtensionPrefStoreTest

tools/heapcheck/suppressions.txt

Index: tools/heapcheck/suppressions.txt
diff --git a/tools/heapcheck/suppressions.txt b/tools/heapcheck/suppressions.txt
index 9a9485f896d17035ec6c2204743a6a8bc1c8f2a9..7ea0448ff992086066b379f46ea13b3da2f34a90 100644
--- a/tools/heapcheck/suppressions.txt
+++ b/tools/heapcheck/suppressions.txt
@@ -839,3 +839,35 @@
    fun:ThreadFunc
    fun:start_thread
 }
+{
+   48980_a
+   Heapcheck:Leak
+   fun:MockPrefService
+   fun:ExtensionPrefStoreTest_NotifyWhenNeeded_Test::TestBody
+}
+{
+   48980_b
+   Heapcheck:Leak
+   ...
+   fun:PrefService::RegisterStringPref
+   fun:ExtensionPrefStoreTest_*_Test::TestBody
+}
+{
+   48980_c
+   Heapcheck:Leak
+   ...
+   fun:ExtensionPrefStore::InstallExtensionPref
+}
+{
+   48980_d
+   Heapcheck:Leak
+   ...
+   fun:basic_string
+   fun:ExtensionPrefStoreTest_*_Test::TestBody
+}
+{
+   48980_e
+   Heapcheck:Leak
+   fun:Value::CreateStringValue
+   fun:ExtensionPrefStoreTest_*_Test::TestBody
+}