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

chrome/browser/chromeos/login/ui/login_display_host_impl.cc

Index: chrome/browser/chromeos/login/ui/login_display_host_impl.cc
diff --git a/chrome/browser/chromeos/login/ui/login_display_host_impl.cc b/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
index be3a303249bbf552237ffa3fec6e0b674a9d7444..55829d081fe1252dd748f557a80b72507f3b9bf0 100644
--- a/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
+++ b/chrome/browser/chromeos/login/ui/login_display_host_impl.cc
@@ -83,6 +83,7 @@
 #include "ui/gfx/rect.h"
 #include "ui/gfx/transform.h"
 #include "ui/keyboard/keyboard_controller.h"
+#include "ui/keyboard/keyboard_util.h"
 #include "ui/views/focus/focus_manager.h"
 #include "ui/views/widget/widget.h"
 #include "ui/views/widget/widget_delegate.h"
@@ -282,6 +283,24 @@ class LoginWidgetDelegate : public views::WidgetDelegate {
   DISALLOW_COPY_AND_ASSIGN(LoginWidgetDelegate);
 };
 
+// Returns true if login should scroll user pods into view itself when virtual
+// keyboard is shown and disable vk overscroll.
+bool LoginScrollIntoViewEnabled() {
+  return !CommandLine::ForCurrentProcess()->HasSwitch(
+      chromeos::switches::kDisableLoginScrollIntoView);
+}
+
+// Disables virtual keyboard overscroll. Login UI will scroll user pods
+// into view on JS side when virtual keyboard is shown.
+void DisableKeyboardOverscroll() {
+  keyboard::SetKeyboardOverscrollEnabledOverrideValue(false);
+  keyboard::SetKeyboardOverscrollOverrideEnabled(true);
+}
+
+void ResetKeyboardOverscrollOverride() {
+  keyboard::SetKeyboardOverscrollOverrideEnabled(false);
+}
+
 }  // namespace
 
 namespace chromeos {
@@ -435,6 +454,9 @@ LoginDisplayHostImpl::~LoginDisplayHostImpl() {
   ash::Shell::GetInstance()->delegate()->
       RemoveVirtualKeyboardStateObserver(this);
 
+  if (LoginScrollIntoViewEnabled())
+    ResetKeyboardOverscrollOverride();
+
   views::FocusManager::set_arrow_key_traversal_enabled(false);
   ResetLoginWindowAndView();
 
@@ -530,6 +552,9 @@ AutoEnrollmentController* LoginDisplayHostImpl::GetAutoEnrollmentController() {
 void LoginDisplayHostImpl::StartWizard(
     const std::string& first_screen_name,
     scoped_ptr<base::DictionaryValue> screen_parameters) {
+  if (LoginScrollIntoViewEnabled())
+    DisableKeyboardOverscroll();
+
   startup_sound_honors_spoken_feedback_ = true;
   TryToPlayStartupSound();
 
@@ -574,6 +599,9 @@ AppLaunchController* LoginDisplayHostImpl::GetAppLaunchController() {
 
 void LoginDisplayHostImpl::StartUserAdding(
     const base::Closure& completion_callback) {
+  if (LoginScrollIntoViewEnabled())
+    DisableKeyboardOverscroll();
+
   restore_path_ = RESTORE_ADD_USER_INTO_SESSION;
   completion_callback_ = completion_callback;
   finalize_animation_type_ = ANIMATION_NONE;
@@ -606,6 +634,9 @@ void LoginDisplayHostImpl::StartUserAdding(
 
 void LoginDisplayHostImpl::StartSignInScreen(
     const LoginScreenContext& context) {
+  if (LoginScrollIntoViewEnabled())
+    DisableKeyboardOverscroll();
+
   startup_sound_honors_spoken_feedback_ = true;
   TryToPlayStartupSound();
 
@@ -876,12 +907,18 @@ void LoginDisplayHostImpl::OnKeyboardBoundsChanging(
     const gfx::Rect& new_bounds) {
   if (new_bounds.IsEmpty() && !keyboard_bounds_.IsEmpty()) {
     // Keyboard has been hidden.
-    if (webui_login_display_)
+    if (webui_login_display_) {

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

Shouldn't we also set keyboard state once webui_login_display_ became available
(in CreateLoginDisplay method)?

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

When CreateLoginDisplay() is called neither handler is created nor JS side is
initialized.

Added to CoreOobeHandler::Initialize().

       webui_login_display_->ShowControlBar(true);
+      if (LoginScrollIntoViewEnabled())
+        webui_login_display_->SetKeyboardState(false);
+    }
   } else if (!new_bounds.IsEmpty() && keyboard_bounds_.IsEmpty()) {
     // Keyboard has been shown.
-    if (webui_login_display_)
+    if (webui_login_display_) {
       webui_login_display_->ShowControlBar(false);
+      if (LoginScrollIntoViewEnabled())
+        webui_login_display_->SetKeyboardState(true);
+    }
   }
 
   keyboard_bounds_ = new_bounds;