Revert "Implement timers by posting delayed tasks"

Source/platform/SharedTimer.h

 /*
  * Copyright (C) 2006 Apple Computer, 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 SQLiteTransaction_h
-#define SQLiteTransaction_h
+#ifndef SharedTimer_h
+#define SharedTimer_h
 
+#include "platform/PlatformExport.h"
 #include "wtf/FastAllocBase.h"
 #include "wtf/Noncopyable.h"
 
 namespace blink {
 
-class SQLiteDatabase;
+// Each thread has its own single instance of shared timer, which implements this interface.
+// This instance is shared by all timers in the thread.
+// Not intended to be used directly; use the Timer class instead.
+class PLATFORM_EXPORT SharedTimer {
+    WTF_MAKE_NONCOPYABLE(SharedTimer); WTF_MAKE_FAST_ALLOCATED(SharedTimer);
+public:
+    SharedTimer() { }
+    virtual ~SharedTimer() {}
+    virtual void setFiredFunction(void (*)()) = 0;
 
-class SQLiteTransaction {
-    WTF_MAKE_NONCOPYABLE(SQLiteTransaction); WTF_MAKE_FAST_ALLOCATED(SQLiteTransaction);
+    // The fire interval is in seconds relative to the current monotonic clock time.
+    virtual void setFireInterval(double) = 0;
+    virtual void stop() = 0;
+};
+
+
+PLATFORM_EXPORT void setSharedTimerFiredFunction(void (*)());
+PLATFORM_EXPORT void setSharedTimerFireInterval(double);
+PLATFORM_EXPORT void stopSharedTimer();
+
+class PLATFORM_EXPORT MainThreadSharedTimer : public SharedTimer {
 public:
-    SQLiteTransaction(SQLiteDatabase& db, bool readOnly = false);
-    ~SQLiteTransaction();
+    virtual void setFiredFunction(void (*function)()) override
+    {
+        setSharedTimerFiredFunction(function);
+    }
 
-    void begin();
-    void commit();
-    void rollback();
-    void stop();
+    virtual void setFireInterval(double interval) override
+    {
+        setSharedTimerFireInterval(interval);
+    }
 
-    bool inProgress() const { return m_inProgress; }
-    bool wasRolledBackBySqlite() const;
-private:
-    SQLiteDatabase& m_db;
-    bool m_inProgress;
-    bool m_readOnly;
+    virtual void stop() override
+    {
+        stopSharedTimer();
+    }
 };
 
 } // namespace blink
 
-#endif // SQLiteTransation_H
+#endif // SharedTimer_h