WIP: WebLayer::addAnimation should transfer the ownership of WebAnimation instance.

public/platform/WebPassOwnPtr.h

Index: public/platform/WebPassOwnPtr.h
diff --git a/public/platform/WebPrivateOwnPtr.h b/public/platform/WebPassOwnPtr.h
similarity index 50%
copy from public/platform/WebPrivateOwnPtr.h
copy to public/platform/WebPassOwnPtr.h
index 5e13f07b348bc9749d69a4d2e957ca0eea297910..9c53d8f597c1e1f25b8549a539e4ae3a9263cc08 100644
--- a/public/platform/WebPrivateOwnPtr.h
+++ b/public/platform/WebPassOwnPtr.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010 Google Inc. All rights reserved.
+ * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,53 +23,73 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebPrivateOwnPtr_h
-#define WebPrivateOwnPtr_h
+#ifndef WebPassOwnPtr_h
+#define WebPassOwnPtr_h
 
 #include "WebCommon.h"
 
+#if INSIDE_BLINK
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/UnusedParam.h"
+#endif
+
 namespace WebKit {
 
-// This class is an implementation detail of the WebKit API.  It exists
-// to help simplify the implementation of WebKit interfaces that merely
-// wrap a pointer to a WebCore class. It's similar to WebPrivatePtr, but it
-// wraps a naked pointer rather than a reference counted.
-// Note: you must call reset(0) on the implementation side in order to delete
-// the WebCore pointer.
+// It exists to help transfer the ownership of either OwnPtr or PassOwnPtr from Blink to Chromium.
+//
+// A typical usage is as follows:
+// in Blink side
+//   OwnPtr<WebAnimation> animation;
+//   WebLayer layer;
+//   layer->addAnimation(animation);
+//
+// in Chromium side
+//   bool WebAnimation::addAnimation(WebPassOwnPtr<WebAnimation> pop_animation) {
+//     scoped_ptr<WebAnimation> animation(pop_animation.leakPtr());
+//     ...
+//   }
 template <typename T>
-class WebPrivateOwnPtr {
+class WebPassOwnPtr {
 public:
-    WebPrivateOwnPtr() : m_ptr(0) {}
-    ~WebPrivateOwnPtr() { BLINK_ASSERT(!m_ptr); }
+    WebPassOwnPtr() : m_ptr(0) { }
+    ~WebPassOwnPtr() { BLINK_ASSERT(!m_ptr); delete m_ptr; }
+    WebPassOwnPtr(const WebPassOwnPtr& o) : m_ptr(o.leakPtr()) { }
 
-#if INSIDE_BLINK
-    explicit WebPrivateOwnPtr(T* ptr)
-        : m_ptr(ptr)
+    T* leakPtr() const
     {
+        T* ptr = m_ptr;
+        m_ptr = 0;
+        return ptr;
     }
 
-    void reset(T* ptr)
+#if INSIDE_BLINK
+    explicit WebPassOwnPtr(T* ptr)
+        : m_ptr(ptr)
     {
-        delete m_ptr;
-        m_ptr = ptr;
+        COMPILE_ASSERT(sizeof(T) > 0, TypeMustBeComplete);
     }
 
-    T* get() const { return m_ptr; }
-
-    T* operator->() const
-    {
-        BLINK_ASSERT(m_ptr);
-        return m_ptr;
-    }
+    template<typename U> WebPassOwnPtr(const PassOwnPtr<U>&);
 #endif // INSIDE_BLINK
 
 private:
-    T* m_ptr;
+    WebPassOwnPtr& operator=(const WebPassOwnPtr&);
 
-    WebPrivateOwnPtr(const WebPrivateOwnPtr&);
-    void operator=(const WebPrivateOwnPtr&);
+    mutable T* m_ptr;
 };
 
+#if INSIDE_BLINK
+template<typename T> template<typename U> inline WebPassOwnPtr<T>::WebPassOwnPtr(const PassOwnPtr<U>& o)
+    : m_ptr(o.leakPtr())
+{
+    using WTF::EnableIf;
+    using WTF::IsPointerConvertible;
+    EnsurePtrConvertibleArgDefn(U, T) typeChecker = true;
+    UNUSED_PARAM(typeChecker);
+}
+#endif
+
 } // namespace WebKit
 
 #endif