Add a trivial logging wrapper around console.log, and add some useful log

chrome/browser/resources/hotword/logging.js

Index: chrome/browser/resources/hotword/logging.js
diff --git a/chrome/browser/resources/hotword/logging.js b/chrome/browser/resources/hotword/logging.js
new file mode 100644
index 0000000000000000000000000000000000000000..c6c34e60ddc74d9556d6fd42d322e1de5dd4ee62
--- /dev/null
+++ b/chrome/browser/resources/hotword/logging.js
@@ -0,0 +1,23 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.

[Dan Beam, 2014/09/29 23:45:45]

s/ (c)//

[Anand Mistry (off Chromium), 2014/09/30 03:41:09]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.define('hotword', function() {
+  'use strict';
+
+  var DEBUG = false;

[Dan Beam, 2014/09/29 23:45:44]

why not some externally visible member (e.g. hotword.DEBUG)?  you can set this
from outside the program (in addition to changing the code locally).

[Anand Mistry (off Chromium), 2014/09/30 03:41:10]

Done.

+
+  /**
+   * Wrapper around console.log allowing debug log message to be enabled during
+   * development.
+   */
+  function Debug() {
+    if (DEBUG) {

[Dan Beam, 2014/09/29 23:45:45]

nit: chrome-code generally doesn't use {} for 1-line conditionals

[Anand Mistry (off Chromium), 2014/09/30 03:41:09]

Oops. That one slipped by.

+      console.log.apply(console, arguments);
+    }

[Dan Beam, 2014/09/29 23:45:44]

nit: if you already need to change the code locally, why not:

  if (0)

or

  // Uncomment for glorious debug log spam.
  // console.log.apply(console, arguments);

[Anand Mistry (off Chromium), 2014/09/30 03:41:09]

I like the idea to expose DEBUG so I can enable it at runtime, so I've done that
instead.

+  }
+
+  return {
+    Debug: Debug

[Dan Beam, 2014/09/29 23:45:44]

Debug => debug

[Anand Mistry (off Chromium), 2014/09/30 03:41:10]

Done.

+  };
+});