Add WTF::DiscardableMemory.

Source/wtf/WTFPlatform.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:
  *
  * 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 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
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include "config.h"
-#include "core/testing/UnitTestHelpers.h"
+#ifndef WTF_WTFPlatform_h
+#define WTF_WTFPlatform_h
 
-#include "public/platform/Platform.h"
-#include "public/platform/WebThread.h"
+#include "wtf/Assertions.h"
+#include "wtf/DiscardableMemory.h"
+#include "wtf/PassOwnPtr.h"
 
+namespace WTF {
 
-namespace WebCore {
-namespace testing {
+class WTFPlatform {
+public:
+    virtual ~WTFPlatform() { }
 
-class QuitTask : public blink::WebThread::Task {
-public:
-    virtual void run()
-    {
-        blink::Platform::current()->currentThread()->exitRunLoop();
-    }
+    virtual PassOwnPtr<DiscardableMemory> allocateAndLockDiscardableMemory(size_t bytes) = 0;
+
+    static WTFPlatform* getInstance() { return s_instance; }
+    static void setInstance(WTFPlatform* instance) { ASSERT(!s_instance); s_instance = instance; }
+
+private:
+    static WTFPlatform* s_instance;
 };
 
-void runPendingTasks()
-{
-    blink::Platform::current()->currentThread()->postTask(new QuitTask);
-    blink::Platform::current()->currentThread()->enterRunLoop();
-}
+} // namespace WTF
 
-}
-}
+#endif