Alt remapping doesn't work when Shift is pressed on ChromeOS

ui/events/keycodes/keyboard_code_conversion_xkb.cc

 // Copyright 2014 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.
 
 #include "ui/events/keycodes/keyboard_code_conversion_xkb.h"
 
 #include "ui/events/keycodes/dom/dom_key.h"
 #include "ui/events/keycodes/keyboard_code_conversion.h"
 
 #ifndef XK_dead_greek
@@ skipping 177 matching lines @@
     case XKB_KEY_F24:
       return DomKey::F24;
     case XKB_KEY_Shift_L:
     case XKB_KEY_Shift_R:
       return DomKey::SHIFT;
     case XKB_KEY_Control_L:
     case XKB_KEY_Control_R:
       return DomKey::CONTROL;
     case XKB_KEY_Caps_Lock:
       return DomKey::CAPS_LOCK;
+#if defined(OS_CHROMEOS)
+    case XKB_KEY_Meta_L:
+    case XKB_KEY_Meta_R:
+    case XKB_KEY_Alt_L:
+    case XKB_KEY_Alt_R:
+      // The Shift+Alt generates a KeySym for the Meta key. On ChromeOS the Meta
+      // key is not used and we should still get the Alt key. crbug.com/541468.
+      return DomKey::ALT;
+#else
     case XKB_KEY_Meta_L:
     case XKB_KEY_Meta_R:
       return DomKey::META;
     case XKB_KEY_Alt_L:
     case XKB_KEY_Alt_R:
       return DomKey::ALT;
+#endif  // defined(OS_CHROMEOS)
     case XKB_KEY_Super_L:
     case XKB_KEY_Super_R:
       return DomKey::OS;
     case XKB_KEY_Hyper_L:
     case XKB_KEY_Hyper_R:
       return DomKey::HYPER;
     case XKB_KEY_Delete:
       return DomKey::DEL;
     case XKB_KEY_SunProps:
       return DomKey::PROPS;
@@ skipping 247 matching lines @@
 }
 
 DomKey XKeySymToDomKey(xkb_keysym_t keysym, base::char16 character) {
   DomKey dom_key = NonPrintableXKeySymToDomKey(keysym);
   if (dom_key != DomKey::NONE)
     return dom_key;
   return DomKey::FromCharacter(character);
 }
 
 }  // namespace ui