Test util to allow MultiThreaded tests on TSan

third_party/WebKit/Source/core/css/threaded/MultiThreadedTestUtil.h

Index: third_party/WebKit/Source/core/css/threaded/MultiThreadedTestUtil.h
diff --git a/third_party/WebKit/Source/core/css/threaded/MultiThreadedTestUtil.h b/third_party/WebKit/Source/core/css/threaded/MultiThreadedTestUtil.h
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+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+#include "platform/CrossThreadFunctional.h"
+#include "platform/WaitableEvent.h"
+#include "platform/WebTaskRunner.h"
+#include "platform/scheduler/child/web_scheduler.h"
+#include "platform/wtf/Functional.h"
+#include "platform/wtf/RefCounted.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebThread.h"
+
+namespace blink {
+
+class MultiThreadedTest : public testing::Test {
+ public:
+  // RunOnThreads run a closure num_threads * callbacks_per_thread times.
+  // The default for this is 10*100 = 1000 times.
+
+  template <typename FunctionType, typename... Ps>
+  void RunOnThreads(FunctionType function, Ps&&... parameters) {
+    Vector<std::unique_ptr<WebThread>> threads;
+    Vector<std::unique_ptr<WaitableEvent>> waits;
+
+    for (int i = 0; i < num_threads_; ++i) {
+      threads.push_back(Platform::Current()->CreateThread(""));
+      waits.push_back(WTF::MakeUnique<WaitableEvent>());
+    }
+
+    for (int i = 0; i < num_threads_; ++i) {
+      WebTaskRunner* task_runner = threads[i]->GetWebTaskRunner();
+
+      for (int j = 0; j < callbacks_per_thread_; ++j) {
+        task_runner->PostTask(FROM_HERE,
+                              CrossThreadBind(function, parameters...));
+      }
+
+      task_runner->PostTask(
+          FROM_HERE, CrossThreadBind([](WaitableEvent* w) { w->Signal(); },
+                                     CrossThreadUnretained(waits[i].get())));
+    }
+
+    for (int i = 0; i < num_threads_; ++i) {
+      waits[i]->Wait();
+    }
+  }
+
+ protected:
+  int num_threads_ = 10;
+  int callbacks_per_thread_ = 100;
+};
+
+}  // namespace blink