DevTools: add CSS completion for contain property.

third_party/WebKit/Source/devtools/front_end/sdk/CSSMetadata.js

 /*
  * Copyright (C) 2010 Nikita Vasilyev. All rights reserved.
  * Copyright (C) 2010 Joseph Pecoraro. All rights reserved.
  * Copyright (C) 2010 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
@@ skipping 275 matching lines @@
     ] },
     "margin-bottom-collapse": { values: [
         "collapse",  "separate", "discard"
     ] },
     "box-reflect": { values: [
         "left", "right", "above", "below"
     ] },
     "overflow": { values: [
         "hidden", "auto", "visible", "overlay", "scroll"
     ] },
+    "contain": { values: [
+        "none", "strict", "content", "size", "layout", "style", "paint"
+    ] },
     "text-rendering": { values: [
         "auto", "optimizeSpeed", "optimizeLegibility", "geometricPrecision"
     ] },
     "text-align": { values: [
         "-webkit-auto", "start", "end", "left", "right", "center", "justify", "-webkit-left", "-webkit-right", "-webkit-center"
     ] },
     "list-style-position": { values: [
         "outside", "inside", "hanging"
     ] },
     "margin-bottom": { values: [
@@ skipping 778 matching lines @@
      * @param {string} longhand
      * @return {?Array.<string>}
      */
     shorthands: function(longhand)
     {
         return this._shorthands[longhand];
     }
 }
 
 WebInspector.CSSMetadata.initializeWithSupportedProperties([]);