Revert "Remove OwnPtr from Blink."

third_party/WebKit/Source/wtf/Forward.h

Index: third_party/WebKit/Source/wtf/Forward.h
diff --git a/third_party/WebKit/Source/wtf/Forward.h b/third_party/WebKit/Source/wtf/Forward.h
index 521fffe8311dd7c3be4305d4ae064d2cff86e2cc..03f1333b5364970194773db9dda0d1eafef0e7c5 100644
--- a/third_party/WebKit/Source/wtf/Forward.h
+++ b/third_party/WebKit/Source/wtf/Forward.h
@@ -26,6 +26,15 @@
 
 namespace WTF {
 
+template <typename T> class OwnPtr;
+#if COMPILER(MSVC)
+#ifndef PassOwnPtr
+#define PassOwnPtr OwnPtr
+#endif
+#else
+template <typename T>
+using PassOwnPtr = OwnPtr<T>;
+#endif
 template <typename T> class PassRefPtr;
 template <typename T> class RefPtr;
 template <size_t size> class SizeSpecificPartitionAllocator;
@@ -54,6 +63,8 @@ class Uint32Array;
 
 } // namespace WTF
 
+using WTF::OwnPtr;
+using WTF::PassOwnPtr;
 using WTF::PassRefPtr;
 using WTF::RefPtr;
 using WTF::Vector;