Made conversions from PassRefPtr to WebPrivatePtr move only.

third_party/WebKit/public/platform/WebPrivatePtr.h

Index: third_party/WebKit/public/platform/WebPrivatePtr.h
diff --git a/third_party/WebKit/public/platform/WebPrivatePtr.h b/third_party/WebKit/public/platform/WebPrivatePtr.h
index 1349d00c82d7d4890d4d3a0a6c859a35c6a22598..62399d759bb1d80b47e4666610be1eca63edfed8 100644
--- a/third_party/WebKit/public/platform/WebPrivatePtr.h
+++ b/third_party/WebKit/public/platform/WebPrivatePtr.h
@@ -97,7 +97,7 @@ class PtrStorageImpl<T,
  public:
   typedef PassRefPtr<T> BlinkPtrType;
 
-  void Assign(const BlinkPtrType& val) {
+  void Assign(BlinkPtrType&& val) {
     static_assert(
         crossThreadDestruction == kWebPrivatePtrDestructionSameThread ||
             WTF::IsSubclassOfTemplate<T, WTF::ThreadSafeRefCounted>::value,
@@ -285,8 +285,8 @@ class WebPrivatePtr {
 
 #if INSIDE_BLINK
   template <typename U>
-  WebPrivatePtr(const U& ptr) : storage_(0) {
-    Storage().Assign(ptr);
+  WebPrivatePtr(U&& ptr) : storage_(0) {
+    Storage().Assign(std::forward<U>(ptr));
   }
 
   void Reset() { Storage().Release(); }
@@ -297,8 +297,8 @@ class WebPrivatePtr {
   }
 
   template <typename U>
-  WebPrivatePtr& operator=(const U& ptr) {
-    Storage().Assign(ptr);
+  WebPrivatePtr& operator=(U&& ptr) {
+    Storage().Assign(std::forward<U>(ptr));
     return *this;
   }