[css-flexbox] Don't add extra space-between space at the end

third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 1852 matching lines @@
     LayoutUnit childMainExtent = mainAxisExtentForChild(*child);
     // In an RTL column situation, this will apply the margin-right/margin-end
     // on the left. This will be fixed later in flipForRightToLeftColumn.
     LayoutPoint childLocation(
         shouldFlipMainAxis ? totalMainExtent - mainAxisOffset - childMainExtent
                            : mainAxisOffset,
         crossAxisOffset + flowAwareMarginBeforeForChild(*child));
     setFlowAwareLocationForChild(*child, childLocation);
     mainAxisOffset += childMainExtent + flowAwareMarginEndForChild(*child);
 
-    mainAxisOffset += justifyContentSpaceBetweenChildren(
-        availableFreeSpace, distribution, children.size());
+    if (i != children.size() - 1) {
+      // The last item does not get extra space added.
+      mainAxisOffset += justifyContentSpaceBetweenChildren(
+          availableFreeSpace, distribution, children.size());
+    }
 
     if (isPaginated)
       updateFragmentationInfoForChild(*child);
   }
 
   if (isColumnFlow())
     setLogicalHeight(std::max(
         logicalHeight(), mainAxisOffset + flowAwareBorderEnd() +
                              flowAwarePaddingEnd() + scrollbarLogicalHeight()));
 
@@ skipping 298 matching lines @@
       LayoutUnit originalOffset =
           lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
       LayoutUnit newOffset =
           contentExtent - originalOffset - lineCrossAxisExtent;
       adjustAlignmentForChild(*flexItem.box, newOffset - originalOffset);
     }
   }
 }
 
 }  // namespace blink