Disable VK overscroll for login/out-of-box.

chrome/browser/resources/login/display_manager.js

Index: chrome/browser/resources/login/display_manager.js
diff --git a/chrome/browser/resources/login/display_manager.js b/chrome/browser/resources/login/display_manager.js
index 35f262bedcb1e0b08a08cd80253884d23c6a7aea..0cc5df0c93ce410b688a1a098f1ad276bef68167 100644
--- a/chrome/browser/resources/login/display_manager.js
+++ b/chrome/browser/resources/login/display_manager.js
@@ -173,6 +173,12 @@ cr.define('cr.ui.login', function() {
     forceKeyboardFlow_: false,
 
     /**
+     * Whether virtual keyboard is shown.
+     * @type {boolean}
+     */
+    virtualKeyboardShown_: false,
+
+    /**
      * Type of UI.
      * @type {string}
      */
@@ -226,6 +232,18 @@ cr.define('cr.ui.login', function() {
     },
 
     /**
+     * Virtual keyboard state (hidden/shown).
+     * @param {boolean} hidden Whether keyboard is shown.
+     */
+    get virtualKeyboardShown() {
+      return this.virtualKeyboardShown_;
+    },
+
+    set virtualKeyboardShown(shown) {
+      this.virtualKeyboardShown_ = shown;
+    },
+
+    /**
      * Toggles background of main body between transparency and solid.
      * @param {boolean} solid Whether to show a solid background.
      */
@@ -709,7 +727,7 @@ cr.define('cr.ui.login', function() {
     onWindowResize_: function() {
       var currentScreenId = this.screens_[this.currentStep_];
       var currentScreen = $(currentScreenId);
-      if (currentScreen)
+      if (currentScreen && currentScreen.onWindowResize)

[dzhioev (left Google), 2014/05/21 17:30:32]

Added check is not needed, because we have default implementation of
|onWindowResize| in Screen prototype.

[Nikita (slow), 2014/05/22 15:11:50]

Cool, removed.

         currentScreen.onWindowResize();
     },