Bug 1313767: Deobfuscate events/core.js r=rpl

MozReview-Commit-ID: Ktj70L3DcQF

addon-sdk/source/lib/sdk/util/object.js

@@ -13,6 +13,40 @@ const { flatten } = require('./array');
 const unbind = Function.call.bind(Function.bind, Function.call);
 const slice = unbind(Array.prototype.slice);
 
+class DefaultWeakMap extends WeakMap {
+  constructor(createItem, items = undefined) {
+    super(items);
+
+    this.createItem = createItem;
+  }
+
+  get(key) {
+    if (!this.has(key)) {
+      this.set(key, this.createItem(key));
+    }
+
+    return super.get(key);
+  }
+}
+
+class DefaultMap extends Map {
+  constructor(createItem, items = undefined) {
+    super(items);
+
+    this.createItem = createItem;
+  }
+
+  get(key) {
+    if (!this.has(key)) {
+      this.set(key, this.createItem(key));
+    }
+
+    return super.get(key);
+  }
+}
+
+Object.assign(exports, {DefaultMap, DefaultWeakMap});
+
 /**
  * Merges all the properties of all arguments into first argument. If two or
  * more argument objects have own properties with the same name, the property