account-picker: Fix Chrome OS and Desktop versions.

Chrome OS by applying right css
Desktop by partially reverting CL:1824878

Bug: 1008762
Change-Id: Icdd50ca8264d1a49c53f700ff0f9f66ae58fc257
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1829377
Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700744}

chrome/browser/resources/chromeos/login/md_screen_container.css

@@ -123,6 +123,15 @@ html:not([full-screen-dialog]) #oobe.tpm-error-message #inner-container {
   width: 100%;
 }
 
+#oobe.account-picker {
+  max-height: unset;
+  max-width: unset;
+  padding-bottom: unset;
+  padding-inline-end: unset;
+  padding-inline-start: unset;
+  padding-top: unset;
+}
+
 #outer-container.fullscreen,
 #outer-container.fullscreen #oobe,
 #inner-container,

ui/login/display_manager.js

@@ -747,13 +747,36 @@ cr.define('cr.ui.login', function() {
      * @param {!HTMLElement} screen Screen that is being shown.
      */
     updateScreenSize: function(screen) {
+      if (!cr.isChromeOS) {
+        // Have to reset any previously predefined screen size first
+        // so that screen contents would define it instead.
+        $('inner-container').style.height = '';
+        $('inner-container').style.width = '';
+        screen.style.width = '';
+        screen.style.height = '';
+      }
+
       $('outer-container').classList.toggle(
         'fullscreen', screen.classList.contains('fullscreen'));
 
+      var width = screen.getPreferredSize().width;
+      var height = screen.getPreferredSize().height;
+
+      if (!cr.isChromeOS) {
+        if (screen.classList.contains('fullscreen')) {
+          $('inner-container').style.height = '100%';
+          $('inner-container').style.width = '100%';
+        } else {
+          $('inner-container').style.height = height + 'px';
+          $('inner-container').style.width = width + 'px';
+        }
+        // This requires |screen| to have 'box-sizing: border-box'.
+        screen.style.width = width + 'px';
+        screen.style.height = height + 'px';
+        screen.style.margin = 'auto';
+      }
 
       if (this.showingViewsLogin) {
-        var width = screen.getPreferredSize().width;
-        var height = screen.getPreferredSize().height;
         chrome.send('updateOobeDialogSize', [width, height]);
         $('scroll-container').classList.toggle('disable-scroll', true);
         $('inner-container').classList.toggle('disable-scroll', true);