New parser mode for CSSOM @viewport descriptors.

Source/core/css/CSSParser-in.cpp

Index: Source/core/css/CSSParser-in.cpp
diff --git a/Source/core/css/CSSParser-in.cpp b/Source/core/css/CSSParser-in.cpp
index 873c3471a8f9cd410d435620101cc53e3869a61f..ed0d2c63c1686a7b2818e38cd25c3463d58f0946 100644
--- a/Source/core/css/CSSParser-in.cpp
+++ b/Source/core/css/CSSParser-in.cpp
@@ -543,7 +543,7 @@ static bool parseSimpleLengthValue(MutableStylePropertySet* declaration, CSSProp
 {
     ASSERT(!string.isEmpty());
     bool acceptsNegativeNumbers;
-    if (!isSimpleLengthPropertyID(propertyId, acceptsNegativeNumbers))
+    if (cssParserMode == ViewportMode || !isSimpleLengthPropertyID(propertyId, acceptsNegativeNumbers))

[eseidel, 2013/09/17 16:28:55]

So this whole change is to disallow negative numbers?  Which is more strict than
normal strict mode?

[rune, 2013/09/17 20:17:03]

No. This is to avoid the simple-length-fast-path for "width", which is a
shorthand descriptor in @viewport and cannot be parsed as a simple length.

         return false;
 
     unsigned length = string.length();
@@ -1218,6 +1218,7 @@ bool CSSParser::parseValue(MutableStylePropertySet* declaration, CSSPropertyID p
     m_id = propertyID;
     m_important = important;
 
+    StyleDeclarationScope scope(this, declaration);
     cssyyparse(this);

[eseidel, 2013/09/17 16:28:55]

I might have wrapped this in a block, depending on how long you want the scope
to live for after the parse.

[rune, 2013/09/17 20:17:03]

Will do.

[rune, 2013/09/17 20:40:41]

Done.

 
     m_rule = 0;
@@ -1333,7 +1334,10 @@ bool CSSParser::parseDeclaration(MutableStylePropertySet* declaration, const Str
         m_sourceDataHandler->endRuleHeader(1);
         m_sourceDataHandler->startRuleBody(0);
     }
+
+    StyleDeclarationScope scope(this, declaration);
     cssyyparse(this);
+
     m_rule = 0;
 
     bool ok = false;
@@ -1400,7 +1404,9 @@ PassRefPtr<ImmutableStylePropertySet> CSSParser::createStylePropertySet()
     if (unusedEntries)
         results.remove(0, unusedEntries);
 
-    return ImmutableStylePropertySet::create(results.data(), results.size(), m_context.mode);
+    CSSParserMode mode = inViewport() ? ViewportMode : m_context.mode;
+
+    return ImmutableStylePropertySet::create(results.data(), results.size(), mode);
 }
 
 void CSSParser::addPropertyWithPrefixingVariant(CSSPropertyID propId, PassRefPtr<CSSValue> value, bool important, bool implicit)