Rewrite scoped_ptr<T>(NULL) to use the default ctor in sync/.

sync/engine/sync_scheduler_unittest.cc

Index: sync/engine/sync_scheduler_unittest.cc
diff --git a/sync/engine/sync_scheduler_unittest.cc b/sync/engine/sync_scheduler_unittest.cc
index 75f54180d8c250e215c03e97ccc729c3273bde22..add837afd173e33043ccaf7a6cf45274d63c2748 100644
--- a/sync/engine/sync_scheduler_unittest.cc
+++ b/sync/engine/sync_scheduler_unittest.cc
@@ -107,11 +107,7 @@ testing::AssertionResult ModelTypeSetMatchesInvalidationMap(
 static const size_t kMinNumSamples = 5;
 class SyncSchedulerTest : public testing::Test {
  public:
-  SyncSchedulerTest()
-      : weak_ptr_factory_(this),
-        context_(NULL),
-        syncer_(NULL),
-        delay_(NULL) {}
+  SyncSchedulerTest() : weak_ptr_factory_(this), syncer_(NULL), delay_(NULL) {}
 
   class MockDelayProvider : public BackoffDelayProvider {
    public: