Add --keyboard-usability-test flag and always show keyboard unless manually hide

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/logging.h"
@@ skipping 18 matching lines @@
                                ui::EF_NONE);
   root_window->AsRootWindowHostDelegate()->OnHostKeyEvent(&event);
 }
 
 }  // namespace
 
 namespace keyboard {
 
 bool IsKeyboardEnabled() {
   return CommandLine::ForCurrentProcess()->HasSwitch(
-      switches::kEnableVirtualKeyboard);
+      switches::kEnableVirtualKeyboard) ||
+          CommandLine::ForCurrentProcess()->HasSwitch(
+              switches::kKeyboardUsabilityTest);
+
 }
 
 bool InsertText(const base::string16& text, aura::RootWindow* root_window) {
   if (!root_window)
     return false;
 
   ui::InputMethod* input_method = root_window->GetProperty(
       aura::client::kRootWindowInputMethodKey);
   if (!input_method)
     return false;
@@ skipping 170 matching lines @@
 }
 
 void LogKeyboardControlEvent(KeyboardControlEvent event) {
   UMA_HISTOGRAM_ENUMERATION(
       "VirtualKeyboard.KeyboardControlEvent",
       event,
       keyboard::KEYBOARD_CONTROL_MAX);
 }
 
 }  // namespace keyboard