md-settings: Fix back navigation from /resetProfileSettings.

chrome/test/data/webui/settings/reset_page_test.js

Index: chrome/test/data/webui/settings/reset_page_test.js
diff --git a/chrome/test/data/webui/settings/reset_page_test.js b/chrome/test/data/webui/settings/reset_page_test.js
index 964c26bb6ce25cd5c870acd1fc723eb4f6dc90b0..98edfbd688580baf3a2e8048a5f2ec72e215248c 100644
--- a/chrome/test/data/webui/settings/reset_page_test.js
+++ b/chrome/test/data/webui/settings/reset_page_test.js
@@ -86,19 +86,25 @@ cr.define('settings_reset_page', function() {
 
       // Tests that the reset profile banner
       //  - opens the reset profile dialog when the reset button is clicked.
+      //  - reset happens when clicking on the dialog's reset button.
       //  - the reset profile dialog is closed after reset is done.
       test(TestNames.ResetBannerReset, function() {
         var dialog = resetBanner.$$('settings-reset-profile-dialog');
         assertFalse(!!dialog);
         MockInteractions.tap(resetBanner.$['reset']);
         Polymer.dom.flush();
+        assertTrue(resetBanner.showResetProfileDialog_)
         dialog = resetBanner.$$('settings-reset-profile-dialog');
         assertTrue(!!dialog);
 
-        dialog.fire('reset-done');
-        Polymer.dom.flush();
-        assertEquals('none', dialog.style.display);
-        return Promise.resolve();
+        MockInteractions.tap(dialog.$['reset']);

[tommycli, 2016/10/03 20:47:46]

nit: the dialog.$['foo'] pattern seems odd. Any reason it's used instead of the
more common dialog.$.foo pattern?

[alito, 2016/10/03 23:27:17]

No particular reason. I was just following the same pattern that was used
elsewhere in the file. Changed them to use the .$.foo pattern.

+        flush().then(function() {

[tommycli, 2016/10/03 20:47:46]

I wonder if this the then() may be skipped in some cases, since the test exits
once browserProxy.whenCalled resolves.

Perhaps we should do something like:

browserProxy
  .whenCalled('performResetProfileSettings')
  .then(flush())
  .then(function() {
    ...
  });

Please double check my suggestion. This promise stuff is really tricky.

[alito, 2016/10/03 23:27:17]

I think your suggestion seems safer so I've changed to using that pattern. I do
think that there are some safety nets that ensure that promises must all resolve
before the test can pass (based on my recollection of why I would sometimes get
timeout errors when I was trying to fix the tests), but since I'm not 100% sure,
this seems safer.

+          assertFalse(resetBanner.showResetProfileDialog_);
+          dialog = resetBanner.$$('settings-reset-profile-dialog');
+          assertFalse(!!dialog);
+        });
+
+        return browserProxy.whenCalled('performResetProfileSettings');
       });
 
       // Tests that the reset profile banner removes itself from the DOM when
@@ -178,9 +184,11 @@ cr.define('settings_reset_page', function() {
           // Test case where the 'cancel' button is clicked.
           MockInteractions.tap(dialog.$.cancel);
         }).then(function() {
-          return testOpenCloseResetProfileDialog(function(dialog) {
-            // Test case where the 'close' button is clicked.
-            MockInteractions.tap(dialog.$.dialog.getCloseButton());
+          return flush().then(function() {

[tommycli, 2016/10/03 20:47:46]

nit: i think we can linearize the promise chain like...

return testOpenCloseReset(function(dialog) {
  ...
}.then(flush()).then(function() {
  ...
};

Thanks!!

[alito, 2016/10/03 23:27:17]

Done.

+            return testOpenCloseResetProfileDialog(function(dialog) {
+              // Test case where the 'close' button is clicked.
+              MockInteractions.tap(dialog.$.dialog.getCloseButton());
+            });
           });
         });
       });