Revert of Fix CapsLock remapping. (patchset #2 id:20001 of...

Revert of Fix CapsLock remapping. (patchset #2 id:20001 of https://codereview.chromium.org/959923002/)

Reason for revert:
EventConverterEvdevImplTest.KeyWithLock failing consistently on Linux ChromiumOS Ozone Tests (1).

Original issue's description:
> Fix CapsLock remapping.
>
> Emulates the ChromeOS/X11 method of using F16 and Mod3 to
> represent the caps lock key before remapping.
>
> BUG=461485
> TEST=On device with external keyboard
>
> Committed: https://crrev.com/5fdc45c765de00dd9143879864fa57c7d133e309
> Cr-Commit-Position: refs/heads/master@{#318240}

TBR=spang@chromium.org,derat@chromium.org,kpschoedel@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=461485

Review URL: https://codereview.chromium.org/965473002

Cr-Commit-Position: refs/heads/master@{#318278}

ui/events/ozone/evdev/event_modifiers_evdev.cc

@@ -23,7 +23,6 @@ static const int kEventFlagFromModifiers[] = {
     EF_RIGHT_MOUSE_BUTTON,   // EVDEV_MODIFIER_RIGHT_MOUSE_BUTTON
     EF_COMMAND_DOWN,         // EVDEV_MODIFIER_COMMAND
     EF_ALTGR_DOWN,           // EVDEV_MODIFIER_ALTGR
-    EF_MOD3_DOWN,            // EVDEV_MODIFIER_MOD3
 };
 
 }  // namespace

ui/events/ozone/evdev/event_modifiers_evdev.h

@@ -21,7 +21,6 @@ enum {
   EVDEV_MODIFIER_RIGHT_MOUSE_BUTTON,
   EVDEV_MODIFIER_COMMAND,
   EVDEV_MODIFIER_ALTGR,
-  EVDEV_MODIFIER_MOD3,
   EVDEV_NUM_MODIFIERS
 };
 

ui/events/ozone/evdev/keyboard_evdev.cc

@@ -46,6 +46,10 @@ int EventFlagToEvdevModifier(int flag) {
   }
 }
 
+bool IsModifierLock(int evdev_modifier) {
+  return evdev_modifier == EVDEV_MODIFIER_CAPS_LOCK;
+}
+
 }  // namespace
 
 KeyboardEvdev::KeyboardEvdev(EventModifiersEvdev* modifiers,
@@ -118,15 +122,8 @@ void KeyboardEvdev::UpdateModifier(int modifier_flag, bool down) {
   if (modifier == EVDEV_MODIFIER_NONE)
     return;
 
-  // TODO post-X11: Revise remapping to not use EF_MOD3_DOWN.
-  // Currently EF_MOD3_DOWN means that the CapsLock key is currently down,
-  // and EF_CAPS_LOCK_DOWN means the caps lock state is enabled (and the
-  // key may or may not be down, but usually isn't). There does need to
-  // to be two different flags, since the physical CapsLock key is subject
-  // to remapping, but the caps lock state (which can be triggered in a
-  // variety of ways) is not.
-  if (modifier == EVDEV_MODIFIER_CAPS_LOCK)
-    modifiers_->UpdateModifier(EVDEV_MODIFIER_MOD3, down);
+  if (IsModifierLock(modifier))
+    modifiers_->UpdateModifierLock(modifier, down);
   else
     modifiers_->UpdateModifier(modifier, down);
 }

ui/events/ozone/layout/layout_util.cc

@@ -546,10 +546,6 @@ int ModifierDomKeyToEventFlag(DomKey key) {
       return EF_ALT_DOWN;
     case DomKey::ALT_GRAPH:
       return EF_ALTGR_DOWN;
-    // ChromeOS uses F16 to represent CapsLock before the rewriting stage,
-    // based on the historical X11 implementation.
-    // TODO post-X11: Switch to use CapsLock uniformly.
-    case DomKey::F16:
     case DomKey::CAPS_LOCK:
       return EF_CAPS_LOCK_DOWN;
     case DomKey::CONTROL: