Avoid hang in OncePtr test with --threads 1

tests/OncePtrTest.cpp

Index: tests/OncePtrTest.cpp
diff --git a/tests/OncePtrTest.cpp b/tests/OncePtrTest.cpp
index b1e4e5d1ae7d3ec238a324201db3bb0d9ae7dd11..9c879745562c62387f1a7f91c47c004c48e31856 100644
--- a/tests/OncePtrTest.cpp
+++ b/tests/OncePtrTest.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "Test.h"
+#include "SkCommonFlags.h"

[Kimmo Kinnunen, 2015/10/27 14:23:12]

forgot to remove this..

 #include "SkOncePtr.h"
 #include "SkTaskGroup.h"
 
@@ -18,8 +19,10 @@ DEF_TEST(OncePtr, r) {
         return new int(5);
     };
 
-    SkAtomic<int> force_a_race(sk_num_cores());
-
+    SkAtomic<int> force_a_race(sk_parallel_for_thread_count());
+    if (force_a_race < 1) {
+        return;
+    }
     sk_parallel_for(sk_num_cores()*4, [&](size_t) {
         force_a_race.fetch_add(-1);
         while (force_a_race.load() > 0);