Replace Timers used in ActiveDOMObject with AsyncMethodRunner

Source/platform/AsyncMethodRunner.h

+/*
+ * Copyright (C) 2013 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef AsyncMethodRunner_h
+#define AsyncMethodRunner_h
+
+#include "platform/Timer.h"
+#include "wtf/FastAllocBase.h"
+#include "wtf/Noncopyable.h"
+
+namespace WebCore {
+
+template <typename TargetClass>
+class AsyncMethodRunner {
+    WTF_MAKE_NONCOPYABLE(AsyncMethodRunner);
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    typedef void (TargetClass::*TargetMethod)();
+
+    AsyncMethodRunner(TargetClass* object, TargetMethod method)
+        : m_timer(this, &AsyncMethodRunner<TargetClass>::fired)
+        , m_object(object)
+        , m_method(method)
+        , m_suspended(false)
+        , m_runWhenResumed(false)
+    {
+    }
+
+    // Schedules to run the method asynchronously. Do nothing if it's already
+    // scheduled. If it's suspended, remember to schedule to run the method when
+    // resume() is called.
+    void runAsync()
+    {
+        if (m_suspended) {
+            ASSERT(!m_timer.isActive());
+            m_runWhenResumed = true;
+            return;
+        }
+
+        if (!m_timer.isActive())
+            m_timer.startOneShot(0);
+    }
+
+    // If it's scheduled to run the method, cancel it and remember to schedule
+    // it again when resume() is called. Mainly for implementing
+    // ActiveDOMObject::suspend().
+    void suspend()
+    {
+        ASSERT(!m_suspended);
+        m_suspended = true;
+
+        if (!m_timer.isActive())
+            return;
+
+        m_timer.stop();
+        m_runWhenResumed = true;
+    }
+
+    // Resumes pending method run.
+    void resume()
+    {
+        ASSERT(m_suspended);
+        m_suspended = false;
+
+        if (!m_runWhenResumed)
+            return;
+
+        m_runWhenResumed = false;
+        m_timer.startOneShot(0);
+    }
+
+    void stop()
+    {
+        if (m_suspended) {
+            ASSERT(!m_timer.isActive());
+            m_runWhenResumed = false;
+            m_suspended = false;
+            return;
+        }
+
+        ASSERT(!m_runWhenResumed);
+        if (m_timer.isActive())
+            m_timer.stop();
+    }
+
+private:
+    virtual void fired(Timer<AsyncMethodRunner<TargetClass> >*) { (m_object->*m_method)(); }
+
+    Timer<AsyncMethodRunner<TargetClass> > m_timer;
+
+    TargetClass* m_object;
+    TargetMethod m_method;
+
+    bool m_suspended;
+    bool m_runWhenResumed;
+};
+
+}
+
+#endif