Fix crash in inspector-protocol/debugger/debugger-pause-dedicated-worker.html

Source/core/inspector/InspectorTaskRunner.cpp

Index: Source/core/inspector/InspectorTaskRunner.cpp
diff --git a/Source/core/inspector/InspectorTaskRunner.cpp b/Source/core/inspector/InspectorTaskRunner.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..34143455da079aeecbbfb4be613404702f6a4d4b
--- /dev/null
+++ b/Source/core/inspector/InspectorTaskRunner.cpp
@@ -0,0 +1,71 @@
+// Copyright 2015 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 "config.h"
+#include "core/inspector/InspectorTaskRunner.h"
+
+#include "wtf/Deque.h"
+#include "wtf/ThreadingPrimitives.h"
+#include <v8.h>
+
+namespace blink {
+
+class InspectorTaskRunner::ThreadSafeTaskQueue {
+    WTF_MAKE_NONCOPYABLE(ThreadSafeTaskQueue);
+public:
+    ThreadSafeTaskQueue() { }
+    PassOwnPtr<Task> tryTake()
+    {
+        MutexLocker lock(m_mutex);
+        if (m_queue.isEmpty())
+            return nullptr;
+        return m_queue.takeFirst();
+    }
+    void append(PassOwnPtr<Task> task)
+    {
+        MutexLocker lock(m_mutex);
+        m_queue.append(task);
+    }
+private:
+    Mutex m_mutex;
+    Deque<OwnPtr<Task>> m_queue;
+};
+
+
+InspectorTaskRunner::InspectorTaskRunner(v8::Isolate* isolate)
+    : m_isolate(isolate)
+    , m_taskQueue(adoptPtr(new ThreadSafeTaskQueue))
+    , m_ignoreInterrupts(false)
+{
+}
+
+InspectorTaskRunner::~InspectorTaskRunner()
+{
+}
+
+void InspectorTaskRunner::interruptAndRun(PassOwnPtr<Task> task)
+{
+    m_taskQueue->append(task);
+    m_isolate->RequestInterrupt(&v8InterruptCallback, this);
+}
+
+void InspectorTaskRunner::runPendingTasks()
+{
+    while (true) {
+        OwnPtr<Task> task = m_taskQueue->tryTake();
+        if (!task)
+            return;
+        task->run();
+    }
+}
+
+void InspectorTaskRunner::v8InterruptCallback(v8::Isolate*, void* data)
+{
+    InspectorTaskRunner* runner = static_cast<InspectorTaskRunner*>(data);
+    if (runner->m_ignoreInterrupts)
+        return;
+    runner->runPendingTasks();
+}
+
+}