diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/utils/SkCountdown.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/utils/SkCountdown.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkCountdown.h"
+#include "SkThread.h"
+
+SkCountdown::SkCountdown(int32_t count)
+: fCount(count) {}
+
+void SkCountdown::reset(int32_t count) {
+    fCount = count;
+}
+
+void SkCountdown::run() {
+    if (sk_atomic_dec(&fCount) == 1) {
+        fReady.lock();
+        fReady.signal();
+        fReady.unlock();
+    }
+}
+
+void SkCountdown::wait() {
+    fReady.lock();
+    while (fCount > 0) {
+        fReady.wait();
+    }
+    fReady.unlock();
+}