Unified icon-buttons used in the new GAIA flow.

chrome/browser/resources/chromeos/login/gaia_buttons.js

 /* Copyright 2015 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.
  */
 
 Polymer('gaia-paper-button', {
   onKeyDown: function(e) {
     if (e.keyCode == 13 || e.keyCode == 32)
       this.fire('tap');
   }
 });
 
-Polymer('gaia-core-icon-button', {
-  onKeyDown: function(e) {
-    if (e.keyCode == 13 || e.keyCode == 32)
-      this.fire('tap');
+Polymer('gaia-icon-button', {
+  ready: function() {
+    this.classList.toggle('custom-appearance', true);
+  },
+
+  onMouseDown: function(e) {
+    /* Prevents button focusing after mouse click. */

[Greg Levin, 2015/05/08 19:18:07]

Is this desirable?  Most buttons seem to retain focus after a mouse click,
including shelf (e.g. Shut down) and GAIA (e.g. NEXT) buttons.  I'd lean towards
removing this, unless it's solving a particular problem.

[dzhioev (left Google), 2015/05/08 21:15:45]

Yes, we do this thing for the most buttons in our UI. Buttons affected in this
CL had such behavior before too (see removed lines in 'screen_gaia_signin.js').
This prevents focusing in "mousedown"->move mouse away->"mouseup" case (see
video https://goo.gl/Hmswa4 ) If I remember things right, UX designers
considered such behavior as an UI glitch.

[Greg Levin, 2015/05/11 14:33:50]

Right, but it's not clear to me that we *want* to prevent focus on
"mousedown"->move mouse away->"mouseup" (md-mma-mu).  As I said above, most of
the other buttons on the login page (ChromeOS and GAIA) take focus on md-mma-mu.
 This is also the default behavior in web pages (md-mma-mu a button or link on a
web page, and that element will be focused), and consequently, in a lot of
places in ChromeOS (e.g. Files app, Settings page).  There are other places
where this doesn't happen, of course... it's not really consistent.

It's not a major issue either way, but it would be nice to have some guidance
from UX.  If we decide to prevent focus-on-md-mma-mu, then we should probably
file bugs against ChromeOS and GAIA to remove this behavior from the rest of the
login screen, just to keep things consistent.

[dzhioev (left Google), 2015/05/11 23:05:57]

Got it, I'll keep current behavior for now and consult with UX about this.

+    e.preventDefault();
   }
 });
 
 Polymer('gaia-raised-on-focus-button', {
   onButtonFocus: function() {
     this.raised = true;
   },
 
   onButtonBlur: function() {
     this.raised = false;
   },
 });