1 files changed, 86 insertions, 0 deletions
diff --git a/third_party/webkit/PerformanceTests/Speedometer/resources/flightjs-example-app/components/flight/lib/compose.js b/third_party/webkit/PerformanceTests/Speedometer/resources/flightjs-example-app/components/flight/lib/compose.js
new file mode 100644
index 0000000000..c1343e7fe8
--- /dev/null
+++ b/third_party/webkit/PerformanceTests/Speedometer/resources/flightjs-example-app/components/flight/lib/compose.js
@@ -0,0 +1,86 @@
+// ==========================================
+// Copyright 2013 Twitter, Inc
+// Licensed under The MIT License
+// http://opensource.org/licenses/MIT
+// ==========================================
+
+"use strict";
+
+define(
+
+  [
+    './utils',
+    '../tools/debug/debug'
+  ],
+
+  function(util, debug) {
+
+    //enumerables are shims - getOwnPropertyDescriptor shim doesn't work
+    var canWriteProtect = debug.enabled && !util.isEnumerable(Object, 'getOwnPropertyDescriptor');
+    //whitelist of unlockable property names
+    var dontLock = ['mixedIn'];
+
+    if (canWriteProtect) {
+      //IE8 getOwnPropertyDescriptor is built-in but throws exeption on non DOM objects
+      try {
+        Object.getOwnPropertyDescriptor(Object, 'keys');
+      } catch(e) {
+        canWriteProtect = false;
+      }
+    }
+
+    function setPropertyWritability(obj, isWritable) {
+      if (!canWriteProtect) {
+        return;
+      }
+
+      var props = Object.create(null);
+
+      Object.keys(obj).forEach(
+        function (key) {
+          if (dontLock.indexOf(key) < 0) {
+            var desc = Object.getOwnPropertyDescriptor(obj, key);
+            desc.writable = isWritable;
+            props[key] = desc;
+          }
+        }
+      );
+
+      Object.defineProperties(obj, props);
+    }
+
+    function unlockProperty(obj, prop, op) {
+      var writable;
+
+      if (!canWriteProtect || !obj.hasOwnProperty(prop)) {
+        op.call(obj);
+        return;
+      }
+
+      writable = Object.getOwnPropertyDescriptor(obj, prop).writable;
+      Object.defineProperty(obj, prop, { writable: true });
+      op.call(obj);
+      Object.defineProperty(obj, prop, { writable: writable });
+    }
+
+    function mixin(base, mixins) {
+      base.mixedIn = base.hasOwnProperty('mixedIn') ? base.mixedIn : [];
+
+      mixins.forEach(function(mixin) {
+        if (base.mixedIn.indexOf(mixin) == -1) {
+          setPropertyWritability(base, false);
+          mixin.call(base);
+          base.mixedIn.push(mixin);
+        }
+      });
+
+      setPropertyWritability(base, true);
+    }
+
+    return {
+      mixin: mixin,
+      unlockProperty: unlockProperty
+    };
+
+  }
+);