gn/linux: warnings as errors, turn on Wextra

ui/keyboard/keyboard_util.cc

 // Copyright (c) 2013 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/keyboard/keyboard_util.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 267 matching lines @@
     }
 
     ui::KeyEvent event(event_type, code, key_name, modifiers);
     ui::EventDispatchDetails details =
         host->event_processor()->OnEventFromSource(&event);
     CHECK(!details.dispatcher_destroyed);
   }
   return true;
 }
 
-const void MarkKeyboardLoadStarted() {
+void MarkKeyboardLoadStarted() {
   if (!g_keyboard_load_time_start.Get().ToInternalValue())
     g_keyboard_load_time_start.Get() = base::Time::Now();
 }
 
-const void MarkKeyboardLoadFinished() {
+void MarkKeyboardLoadFinished() {
   // Possible to get a load finished without a start if navigating directly to
   // chrome://keyboard.
   if (!g_keyboard_load_time_start.Get().ToInternalValue())
     return;
 
   // It should not be possible to finish loading the keyboard without starting
   // to load it first.
   DCHECK(g_keyboard_load_time_start.Get().ToInternalValue());
 
   static bool logged = false;
@@ skipping 73 matching lines @@
 }
 
 void LogKeyboardControlEvent(KeyboardControlEvent event) {
   UMA_HISTOGRAM_ENUMERATION(
       "VirtualKeyboard.KeyboardControlEvent",
       event,
       keyboard::KEYBOARD_CONTROL_MAX);
 }
 
 }  // namespace keyboard