Made conversions from PassRefPtr to WebPrivatePtr move only.

third_party/WebKit/Source/platform/exported/WebData.cpp

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 40 matching lines @@
     return 0;
   return private_->size();
 }
 
 const char* WebData::Data() const {
   if (private_.IsNull())
     return 0;
   return private_->Data();
 }
 
-WebData::WebData(PassRefPtr<SharedBuffer> buffer) : private_(buffer) {}
+WebData::WebData(PassRefPtr<SharedBuffer> buffer)
+    : private_(std::move(buffer)) {}
 
 WebData& WebData::operator=(PassRefPtr<SharedBuffer> buffer) {
-  private_ = buffer;
+  private_ = std::move(buffer);
   return *this;
 }
 
 WebData::operator PassRefPtr<SharedBuffer>() const {
   return PassRefPtr<SharedBuffer>(private_.Get());
 }
 
 }  // namespace blink