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 (!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.
   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