Have srcset respond to viewport changes

Source/core/css/parser/SizesAttributeParser.cpp

Index: Source/core/css/parser/SizesAttributeParser.cpp
diff --git a/Source/core/css/parser/SizesAttributeParser.cpp b/Source/core/css/parser/SizesAttributeParser.cpp
index f4b0e20bd357e5c32725c987ac7a006ea8554186..e13f16ec20ab813b0ba7e46f6dd2f9e0b62bbb02 100644
--- a/Source/core/css/parser/SizesAttributeParser.cpp
+++ b/Source/core/css/parser/SizesAttributeParser.cpp
@@ -12,15 +12,19 @@
 
 namespace WebCore {
 
-unsigned SizesAttributeParser::findEffectiveSize(const String& attribute, PassRefPtr<MediaValues> mediaValues)
+unsigned SizesAttributeParser::findEffectiveSize(const String& attribute, PassRefPtr<MediaValues> mediaValues, bool& viewportDependant)
 {
     Vector<MediaQueryToken> tokens;
+    unsigned size;
     SizesAttributeParser parser(mediaValues);
 
     MediaQueryTokenizer::tokenize(attribute, tokens);
-    if (!parser.parse(tokens))
-        return parser.effectiveSizeDefaultValue();
-    return parser.effectiveSize();
+    if (parser.parse(tokens))
+        size = parser.effectiveSize();
+    else
+        size = parser.effectiveSizeDefaultValue();
+    viewportDependant = parser.viewportDependant();

[esprehn, 2014/07/14 08:39:49]

You should hide this logic inside an instance method.

SizesAttributeParser parser(attribute, mediaValues);
parser.parse();
if (parser.viewportDependant()) {
  ...
}

+    return size;
 }
 
 bool SizesAttributeParser::calculateLengthInPixels(MediaQueryTokenIterator startToken, MediaQueryTokenIterator endToken, unsigned& result)
@@ -32,12 +36,13 @@ bool SizesAttributeParser::calculateLengthInPixels(MediaQueryTokenIterator start
         int length;
         if (!CSSPrimitiveValue::isLength(startToken->unitType()))
             return false;
+        m_viewportDependant = CSSPrimitiveValue::isViewportPercentageLength(startToken->unitType());
         if ((m_mediaValues->computeLength(startToken->numericValue(), startToken->unitType(), length)) && (length > 0)) {
             result = (unsigned)length;
             return true;
         }
     } else if (type == FunctionToken) {
-        return SizesCalcParser::parse(startToken, endToken, m_mediaValues, result);
+        return SizesCalcParser::parse(startToken, endToken, m_mediaValues, result, m_viewportDependant);
     } else if (type == NumberToken && !startToken->numericValue()) {
         result = 0;
         return true;
@@ -133,7 +138,8 @@ unsigned SizesAttributeParser::effectiveSize()
 
 unsigned SizesAttributeParser::effectiveSizeDefaultValue()
 {
-    // Returning the equivalent of "100%"
+    // Returning the equivalent of "100vw"
+    m_viewportDependant = true;
     return m_mediaValues->viewportWidth();
 }