Don't handle the tab press event in the window cycle event filter.

ash/wm/window_cycle_event_filter_aura.cc

Index: ash/wm/window_cycle_event_filter_aura.cc
diff --git a/ash/wm/window_cycle_event_filter_aura.cc b/ash/wm/window_cycle_event_filter_aura.cc
index c0504e9b3fa5b93060d6e9c6b6689a3344f88c6f..fd716f40f14266f69be49afb75699d81130ad393 100644
--- a/ash/wm/window_cycle_event_filter_aura.cc
+++ b/ash/wm/window_cycle_event_filter_aura.cc
@@ -20,9 +20,13 @@ WindowCycleEventFilterAura::~WindowCycleEventFilterAura() {
 }
 
 void WindowCycleEventFilterAura::OnKeyEvent(ui::KeyEvent* event) {
-  // Until the alt key is released, all key events are handled by this window
-  // cycle controller: https://crbug.com/340339.
-  event->StopPropagation();
+  // Until the alt key is released, all key events except the tab press (which
+  // is handled by the accelerator controller to call Step) are handled by this
+  // window cycle controller: https://crbug.com/340339.
+  if (event->key_code() != ui::VKEY_TAB ||
+      event->type() != ui::ET_KEY_PRESSED) {

[varkha, 2016/08/17 18:06:57]

Does this properly deal with Alt+Shift+Tab?

[flackr, 2016/08/17 19:07:19]

Yes.

+    event->StopPropagation();
+  }
   // Views uses VKEY_MENU for both left and right Alt keys.
   if (event->key_code() == ui::VKEY_MENU &&
       event->type() == ui::ET_KEY_RELEASED) {