Add support for threadsafe completion callback factory.

This also makes the default be threadsafe. The old factory wasn't threadsafe even to the extent claimed in the header which was causing hangs in plugins

BUG=136284

Review URL: https://chromiumcodereview.appspot.com/10696157

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@146611 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/ppapi/ppapi_sources.gypi b/ppapi/ppapi_sources.gypi
index 1e5904ac..c5ee4a4 100644
--- a/ppapi/ppapi_sources.gypi
+++ b/ppapi/ppapi_sources.gypi
@@ -300,13 +300,15 @@
 
       # Utility sources.
       'utility/completion_callback_factory.h',
-      'utility/non_thread_safe_ref_count.h',
+      'utility/completion_callback_factory_thread_traits.h',
       'utility/graphics/paint_aggregator.cc',
       'utility/graphics/paint_aggregator.h',
       'utility/graphics/paint_manager.cc',
       'utility/graphics/paint_manager.h',
       'utility/private/network_list_observer_private.cc',
       'utility/private/network_list_observer_private.h',
+      'utility/threading/lock.cc',
+      'utility/threading/lock.h',
       'utility/threading/simple_thread.cc',
       'utility/threading/simple_thread.h',
       'utility/websocket/websocket_api.cc',