Have srcset respond to viewport changes

Source/core/css/parser/SizesCalcParser.h

Index: Source/core/css/parser/SizesCalcParser.h
diff --git a/Source/core/css/parser/SizesCalcParser.h b/Source/core/css/parser/SizesCalcParser.h
index 4e040c6cee66bfef06805c6ce8133258ff524140..46a1a7c6e535dc46112492375dbd68365b13814e 100644
--- a/Source/core/css/parser/SizesCalcParser.h
+++ b/Source/core/css/parser/SizesCalcParser.h
@@ -34,11 +34,13 @@ struct SizesCalcValue {
 class SizesCalcParser {
 
 public:
-    static bool parse(MediaQueryTokenIterator start, MediaQueryTokenIterator end, PassRefPtr<MediaValues>, unsigned& result);
+    static bool parse(MediaQueryTokenIterator start, MediaQueryTokenIterator end, PassRefPtr<MediaValues>, unsigned& result, bool& viewportDependant);
+    bool viewportDependant() const { return m_viewportDependant; }
 
 private:
     SizesCalcParser(PassRefPtr<MediaValues> mediaValues)
         : m_mediaValues(mediaValues)
+        , m_viewportDependant(false)
     {
     }
 
@@ -51,6 +53,7 @@ private:
 
     Vector<SizesCalcValue> m_valueList;
     RefPtr<MediaValues> m_mediaValues;
+    bool m_viewportDependant;
 };
 
 } // namespace WebCore