Don't persist the SVGTextLayoutAttributesBuilder

third_party/WebKit/Source/core/layout/svg/SVGTextLayoutAttributesBuilder.h

 /*
  * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #ifndef SVGTextLayoutAttributesBuilder_h
 #define SVGTextLayoutAttributesBuilder_h
 
 #include "core/layout/svg/SVGTextLayoutAttributes.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Allocator.h"
 #include "wtf/Vector.h"
-#include "wtf/text/Unicode.h"
 
 namespace blink {
 
 class LayoutBoxModelObject;
-class LayoutSVGInlineText;
 class LayoutSVGText;
 class SVGTextPositioningElement;
 
 // SVGTextLayoutAttributesBuilder performs the first layout phase for SVG text.
 //
 // It extracts the x/y/dx/dy/rotate values from the SVGTextPositioningElements in the DOM.
 // These values are propagated to the corresponding LayoutSVGInlineText layoutObjects.
 // The first layout phase only extracts the relevant information needed in LayoutBlockFlowLine
 // to create the InlineBox tree based on text chunk boundaries & BiDi information.
 // The second layout phase is carried out by SVGTextLayoutEngine.
-
 class SVGTextLayoutAttributesBuilder {
-    DISALLOW_NEW();
+    STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(SVGTextLayoutAttributesBuilder);
 public:
-    SVGTextLayoutAttributesBuilder();
+    explicit SVGTextLayoutAttributesBuilder(LayoutSVGText&);
 
-    void buildLayoutAttributesForTextRoot(LayoutSVGText&);
-
-    // Invoked whenever the underlying DOM tree changes, so that m_textPositions is rebuild.
-    void clearTextPositioningElements() { m_textPositions.clear(); }
-    unsigned numberOfTextPositioningElements() const { return m_textPositions.size(); }
+    void buildLayoutAttributes();
 
     struct TextPosition {
         DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
     public:
         TextPosition(SVGTextPositioningElement* newElement = nullptr, unsigned newStart = 0, unsigned newLength = 0)
             : element(newElement)
             , start(newStart)
             , length(newLength)
         {
         }
 
         DECLARE_TRACE();
 
         Member<SVGTextPositioningElement> element;
         unsigned start;
         unsigned length;
     };
 
 private:
     void buildCharacterDataMap(LayoutSVGText&);
     void buildLayoutAttributes(LayoutSVGText&) const;
     void collectTextPositioningElements(LayoutBoxModelObject&);
     void fillCharacterDataMap(const TextPosition&);
 
-private:
+    LayoutSVGText& m_textRoot;
     unsigned m_characterCount;
-    PersistentHeapVector<TextPosition> m_textPositions;
+    HeapVector<TextPosition> m_textPositions;
     SVGCharacterDataMap m_characterDataMap;
 };
 
 } // namespace blink
 
 WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(blink::SVGTextLayoutAttributesBuilder::TextPosition);
 
 #endif