Implement color stop position syntax from CSS Image Values 4

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/parser/CSSPropertyParserHelpers.h"
 
 #include "core/css/CSSCalculationValue.h"
 #include "core/css/CSSColorValue.h"
 #include "core/css/CSSCrossfadeValue.h"
 #include "core/css/CSSGradientValue.h"
@@ skipping 949 matching lines @@
     stop.m_color = consumeColor(range, cssParserMode);
     // Two hints in a row are not allowed.
     if (!stop.m_color && (!supportsColorHints || previousStopWasColorHint))
       return false;
     previousStopWasColorHint = !stop.m_color;
     stop.m_offset = consumePositionFunc(range, cssParserMode, ValueRangeAll,
                                         UnitlessQuirk::Forbid);
     if (!stop.m_color && !stop.m_offset)
       return false;
     gradient->addStop(stop);
+
+    if (RuntimeEnabledFeatures::multipleColorStopPositionsEnabled()) {
+      if (!stop.m_color || !stop.m_offset)
+        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.
   if (previousStopWasColorHint)
     return false;
 
   // Must have 2 or more stops to be valid.
   return gradient->stopCount() >= 2;
 }
 
@@ skipping 427 matching lines @@
 
 // https://drafts.csswg.org/css-shapes-1/#typedef-shape-box
 CSSIdentifierValue* consumeShapeBox(CSSParserTokenRange& range) {
   return consumeIdent<CSSValueContentBox, CSSValuePaddingBox, CSSValueBorderBox,
                       CSSValueMarginBox>(range);
 }
 
 }  // namespace CSSPropertyParserHelpers
 
 }  // namespace blink