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

ash/root_window_controller_unittest.cc

 // Copyright (c) 2012 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 "ash/root_window_controller.h"
 
 #include "ash/session_state_delegate.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
@@ skipping 603 matching lines @@
 
 class VirtualKeyboardRootWindowControllerTest : public test::AshTestBase {
  public:
   VirtualKeyboardRootWindowControllerTest() {};
   virtual ~VirtualKeyboardRootWindowControllerTest() {};
 
   virtual void SetUp() OVERRIDE {
     CommandLine::ForCurrentProcess()->AppendSwitch(
         keyboard::switches::kEnableVirtualKeyboard);
     test::AshTestBase::SetUp();
+    Shell::GetPrimaryRootWindowController()->ActivateKeyboard(
+        Shell::GetInstance()->keyboard_controller());
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(VirtualKeyboardRootWindowControllerTest);
 };
 
 // Test for http://crbug.com/297858. Virtual keyboard container should only show
 // on primary root window.
 TEST_F(VirtualKeyboardRootWindowControllerTest,
        VirtualKeyboardOnPrimaryRootWindowOnly) {
@@ skipping 61 matching lines @@
   aura::WindowTracker tracker;
   tracker.Add(keyboard_container);
   // Mock a login state change to reinitialize the keyboard.
   ash::Shell::GetInstance()->OnLoginStateChanged(user::LOGGED_IN_OWNER);
   // keyboard_container should no longer be present.
   EXPECT_FALSE(tracker.Contains(keyboard_container));
 }
 
 }  // namespace test
 }  // namespace ash