Implement color stop position syntax from CSS Image Values 4

third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp

Index: third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
diff --git a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
index 4f6e0cecc6c56aba31b4fc746fdb41599975ef8b..e9abe6cc5869c2cf78b5bf3a55d3ea04346d64da 100644
--- a/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
+++ b/third_party/WebKit/Source/core/css/parser/CSSPropertyParserHelpers.cpp
@@ -967,6 +967,16 @@ static bool consumeGradientColorStops(CSSParserTokenRange& range,
     if (!stop.m_color && !stop.m_offset)
       return false;
     gradient->addStop(stop);
+
+    if (!stop.m_color || !stop.m_offset ||
+        !RuntimeEnabledFeatures::multipleColorStopPositionsEnabled())

[fs, 2017/04/06 19:58:48]

Ponder: Maybe we could have this as a:

if (RuntimeEnabledFeatures::multipleColorStopPositionsEnabled()) {
  ...parsing of additional offset...
}

block instead?

[f(malita), 2017/04/06 20:29:42]

Done.

+      continue;
+
+    // Optional second position.
+    stop.m_offset = consumePositionFunc(range, cssParserMode, ValueRangeAll,
+                                        UnitlessQuirk::Forbid);
+    if (stop.m_offset)
+      gradient->addStop(stop);
   } while (consumeCommaIncludingWhitespace(range));
 
   // The last color stop cannot be a color hint.