ozone: evdev: Drop unmapped key events

ui/events/ozone/evdev/keyboard_evdev.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/ozone/evdev/keyboard_evdev.h"
 
 #include "ui/events/event.h"
 #include "ui/events/keycodes/dom4/keycode_converter.h"
 #include "ui/events/ozone/evdev/event_modifiers_evdev.h"
 
@@ skipping 210 matching lines @@
   if (locking)
     modifiers_->UpdateModifierLock(modifier, down);
   else
     modifiers_->UpdateModifier(modifier, down);
 }
 
 void KeyboardEvdev::DispatchKey(unsigned int key, bool down) {
   ui::KeyboardCode code = KeyboardCodeFromEvdevKey(key);
   int flags = modifiers_->GetModifierFlags();
 
+  if (code == VKEY_UNKNOWN)
+    return;
+
   callback_.Run(make_scoped_ptr(new KeyEvent(
       down ? ET_KEY_PRESSED : ET_KEY_RELEASED,
       code,
       KeycodeConverter::NativeKeycodeToCode(key + kXkbKeycodeOffset),
       flags)));
 }
 
 }  // namespace ui