[css-grid] Implement grid gutters

Source/core/frame/UseCounter.cpp

 /*
  * Copyright (C) 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 523 matching lines @@
     case CSSPropertyAliasWebkitShapeOutside: return 498;
     case CSSPropertyScrollSnapType: return 499;
     case CSSPropertyScrollSnapPointsX: return 500;
     case CSSPropertyScrollSnapPointsY: return 501;
     case CSSPropertyScrollSnapCoordinate: return 502;
     case CSSPropertyScrollSnapDestination: return 503;
     case CSSPropertyTranslate: return 504;
     case CSSPropertyRotate: return 505;
     case CSSPropertyScale: return 506;
     case CSSPropertyImageOrientation: return 507;
+    case CSSPropertyGridColumnGap: return 508;
+    case CSSPropertyGridRowGap: return 509;
+    case CSSPropertyGridGap: return 510;
 
     // 1. Add new features above this line (don't change the assigned numbers of the existing
     // items).
     // 2. Update maximumCSSSampleId() with the new maximum value.
     // 3. Run the update_use_counter_css.py script in
     // chromium/src/tools/metrics/histograms to update the UMA histogram names.
 
     case CSSPropertyInvalid:
         ASSERT_NOT_REACHED();
         return 0;
     }
 
     ASSERT_NOT_REACHED();
     return 0;
 }
 
-static int maximumCSSSampleId() { return 507; }
+static int maximumCSSSampleId() { return 510; }
 
 void UseCounter::muteForInspector()
 {
     UseCounter::m_muteCount++;
 }
 
 void UseCounter::unmuteForInspector()
 {
     UseCounter::m_muteCount--;
 }
@@ skipping 429 matching lines @@
 UseCounter* UseCounter::getFrom(const StyleSheetContents* sheetContents)
 {
     // FIXME: We may want to handle stylesheets that have multiple owners
     //        http://crbug.com/242125
     if (sheetContents && sheetContents->hasSingleOwnerNode())
         return getFrom(sheetContents->singleOwnerDocument());
     return 0;
 }
 
 } // namespace blink