Replaced PassRefPtr copies with moves in Source/core.

third_party/WebKit/Source/core/layout/api/LayoutTextFragmentItem.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LayoutTextFragmentItem_h
 #define LayoutTextFragmentItem_h
 
 #include "core/layout/LayoutTextFragment.h"
 #include "core/layout/api/LayoutTextItem.h"
 
@@ skipping 13 matching lines @@
     {
         ASSERT_WITH_SECURITY_IMPLICATION(!item || item.isTextFragment());
     }
 
     explicit LayoutTextFragmentItem(std::nullptr_t) : LayoutTextItem(nullptr) { }
 
     LayoutTextFragmentItem() { }
 
     void setTextFragment(PassRefPtr<StringImpl> text, unsigned start, unsigned length)
     {
-        toTextFragment()->setTextFragment(text, start, length);
+        toTextFragment()->setTextFragment(std::move(text), start, length);
     }
 
     FirstLetterPseudoElement* firstLetterPseudoElement() const
     {
         return toTextFragment()->firstLetterPseudoElement();
     }
 
 private:
     LayoutTextFragment* toTextFragment() { return toLayoutTextFragment(layoutObject()); }
     const LayoutTextFragment* toTextFragment() const { return toLayoutTextFragment(layoutObject()); }
 };
 
 } // namespace blink
 
 #endif // LayoutTextFragmentItem_h