Convert Google Now's Authentication Manager to use Promises

chrome/browser/resources/google_now/common_test_util.js

Index: chrome/browser/resources/google_now/common_test_util.js
diff --git a/chrome/browser/resources/google_now/common_test_util.js b/chrome/browser/resources/google_now/common_test_util.js
index 754e2578fa2f6bf059a5b2b70fbb7ea8c6ed0bed..2c475288faaf32c1baeebfc4d66057b1831783c5 100644
--- a/chrome/browser/resources/google_now/common_test_util.js
+++ b/chrome/browser/resources/google_now/common_test_util.js
@@ -82,16 +82,38 @@ function getMockHandlerContainer(eventIdentifier) {
 var Promise = function() {
   function PromisePrototypeObject(asyncTask) {
     var result;
+    var resolved = false;
     asyncTask(
         function(asyncResult) {
           result = asyncResult;
+          resolved = true;
         },
-        function() {}); // Errors are unsupported.
+        function(asyncFailureResult) {
+          result = asyncResult;
+          resolved = false;
+        });
 
     function then(callback) {
-      callback.call(null, result);
+      if (resolved) {
+        callback.call(null, result);
+      }
+      return this;
     }
-    return {then: then, isPromise: true};
+
+    // Promises use the function name catch to call back error handlers.

[skare_, 2014/02/13 23:53:52]

(no action required, just a suggestion based on first reading)
maybe put "catch" in quotes, like:
// Promises call "catch" to ...
// Promises use the function named "catch"

[robliao, 2014/02/14 00:05:11]

Done.

+    // We can't use catch since function or variable names cannot use the word

[skare_, 2014/02/13 23:53:52]

or just "We can't use 'catch' since it's reserved"

[robliao, 2014/02/14 00:05:11]

This isn't strictly true, since it works fine for foo.catch.
Object initialization, function names, and variable names are the few instances
I've found thus far that do not allow this. Variable references, function calls,
on the other hand, are okay.

+    // catch.
+    function catchFunc(callback) {
+      if (!resolved) {
+        callback.call(null, result);
+      }
+      return this;
+    }
+
+    var promiseObj = {then: then, isPromise: true};
+    // Using the name 'catch' above during initialization will trigger an error.
+    promiseObj.catch = catchFunc;

[skare_, 2014/02/13 23:37:03]

does promiseObj.catch = function(...) {} work?

[robliao, 2014/02/13 23:43:20]

It does, but the named functions follows other non-prototype based 'classes' we
have floating around in Google Now.
On 2014/02/13 23:37:03, Travis Skare wrote:

[skare_, 2014/02/13 23:53:52]

return {then: then, isPromise: true, catch: catchFunc} ?

[robliao, 2014/02/14 00:05:11]

This won't work since "catch" is reserved in object initialization.

[skare_, 2014/02/14 00:19:26]

will catch* you in person since I might have constructed the full parallel
example wrong, but this seems ok?
x = function() { return {catch: function(){return 'hi'} }}; (new x).catch()

*sincere apologies

[robliao, 2014/02/14 01:57:04]

And done.
On 2014/02/14 00:19:26, Travis Skare wrote:

+    return promiseObj;
   }
 
   function all(arrayOfPromises) {