[css-align] Adapt content-alignment properties to the new baseline syntax

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc.
  * All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 641 matching lines @@
     ret->append(*list);
   }
   return ret;
 }
 
 static CSSValueList*
 valueForContentPositionAndDistributionWithOverflowAlignment(
     const StyleContentAlignmentData& data,
     CSSValueID normalBehaviorValueID) {
   CSSValueList* result = CSSValueList::createSpaceSeparated();
+  // Handle content-distribution values
   if (data.distribution() != ContentDistributionDefault)
     result->append(*CSSIdentifierValue::create(data.distribution()));
-  if (data.distribution() == ContentDistributionDefault ||
-      data.position() != ContentPositionNormal) {
-    if (!RuntimeEnabledFeatures::cssGridLayoutEnabled() &&
-        data.position() == ContentPositionNormal)
-      result->append(*CSSIdentifierValue::create(normalBehaviorValueID));
-    else
+
+  // Handle content-position values (either as fallback or actual value)
+  switch (data.position()) {
+    case ContentPositionNormal:
+      // Handle 'normal' value, not valid as content-distribution fallback.
+      if (data.distribution() == ContentDistributionDefault) {
+        result->append(*CSSIdentifierValue::create(
+            RuntimeEnabledFeatures::cssGridLayoutEnabled()
+                ? CSSValueNormal
+                : normalBehaviorValueID));
+      }
+      break;
+    case ContentPositionLastBaseline:
+      result->append(
+          *CSSValuePair::create(CSSIdentifierValue::create(CSSValueLast),
+                                CSSIdentifierValue::create(CSSValueBaseline),
+                                CSSValuePair::DropIdenticalValues));
+      break;
+    default:
       result->append(*CSSIdentifierValue::create(data.position()));
   }
+
+  // Handle overflow-alignment (only allowed for content-position values)
   if ((data.position() >= ContentPositionCenter ||
        data.distribution() != ContentDistributionDefault) &&
       data.overflow() != OverflowAlignmentDefault)
     result->append(*CSSIdentifierValue::create(data.overflow()));
   ASSERT(result->length() > 0);
   ASSERT(result->length() <= 3);
   return result;
 }
 
 static CSSValue* valueForLineHeight(const ComputedStyle& style) {
@@ skipping 2993 matching lines @@
     case CSSPropertyAll:
       return nullptr;
     default:
       break;
   }
   ASSERT_NOT_REACHED();
   return nullptr;
 }
 
 }  // namespace blink