[DevTools] Extract platform module.

Source/devtools/front_end/platform/Promise.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @param {string} error
+ * @return {!Promise.<T>}
+ * @template T
+ */
+Promise.rejectWithError = function(error)
+{
+    return Promise.reject(new Error(error));
+}
+
+/**
+ * @param {function((T|undefined))} callback
+ * @return {!Promise.<T>}
+ * @template T
+ */
+Promise.prototype.thenOrCatch = function(callback)
+{
+    return this.then(callback, reject.bind(this));
+
+    /**
+     * @param {*} e
+     * @this {Promise}
+     */
+    function reject(e)
+    {
+        this._reportError(e);
+        callback(undefined);
+    }
+}
+
+Promise.prototype.done = function()
+{
+    this.catchAndReport();
+}
+
+/**
+ * @return {!Promise}
+ */
+Promise.prototype.catchAndReport = function()
+{
+    return this.catch(this._reportError.bind(this));
+}
+
+/**
+ * @param {*} e
+ */
+Promise.prototype._reportError = function(e)
+{
+    if (e instanceof Error)
+        console.error(e.stack);
+    else
+        console.error(e);
+}
+
+// FIXME: This performance optimization should be moved to blink so that all developers could enjoy it.
+// console is retrieved with V8Window.getAttribute method which is slow. Here we copy it to a js variable for faster access.
+console = console;

[apavlov, 2014/10/31 13:26:26]

This is not quite related to promises

[dgozman, 2014/10/31 13:56:06]

Moved to utilities.

+console.__originalAssert = console.assert;
+console.assert = function(value, message)
+{
+    if (value)
+        return;
+    console.__originalAssert(value, message);
+}