Rename DatabaseTaskSynchronizer to TaskSynchronizer and move it to platform/

Source/platform/TaskSynchronizer.h

 /*
- * Copyright (C) 2005, 2006, 2007 Apple Inc.  All rights reserved.
+ * Copyright (C) 2007, 2008, 2013 Apple 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.
  * 3.  Neither the name of Apple Computer, Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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 StringTruncator_h
-#define StringTruncator_h
+#ifndef TaskSynchronizer_h
+#define TaskSynchronizer_h
 
-#include "platform/PlatformExport.h"
-#include "wtf/Forward.h"
+#include "wtf/Noncopyable.h"
+#include "wtf/Threading.h"
+#include "wtf/ThreadingPrimitives.h"
 
 namespace WebCore {
 
-class Font;
+// TaskSynchronizer can be used to wait for task completion.
+class TaskSynchronizer {
+    WTF_MAKE_NONCOPYABLE(TaskSynchronizer);
+public:
+    TaskSynchronizer();
 
-class PLATFORM_EXPORT StringTruncator {
-public:
-    enum EnableRoundingHacksOrNot { DisableRoundingHacks, EnableRoundingHacks };
+    // Called from a thread that waits for the task completion.
+    void waitForTaskCompletion();
 
-    static String centerTruncate(const String&, float maxWidth, const Font&, EnableRoundingHacksOrNot = DisableRoundingHacks);
-    static String rightTruncate(const String&, float maxWidth, const Font&, EnableRoundingHacksOrNot = DisableRoundingHacks);
-    static float width(const String&, const Font&, EnableRoundingHacksOrNot = DisableRoundingHacks);
+    // Called from a thread that executes the task.
+    void taskCompleted();
+
+#ifndef NDEBUG
+    bool hasCheckedForTermination() const { return m_hasCheckedForTermination; }
+    void setHasCheckedForTermination() { m_hasCheckedForTermination = true; }
+#endif
+
+private:
+    bool m_taskCompleted;
+    Mutex m_synchronousMutex;
+    ThreadCondition m_synchronousCondition;
+#ifndef NDEBUG
+    bool m_hasCheckedForTermination;
+#endif
 };
 
-} // namespace WebCore
+}
 
-#endif // !defined(StringTruncator_h)
+#endif // TaskSynchronizer_h