Convert WindowOpenDisposition to an enum class.

ui/keyboard/content/keyboard_ui_content.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/content/keyboard_ui_content.h"
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/values.h"
 #include "content/public/browser/render_widget_host.h"
@@ skipping 278 matching lines @@
 
 const aura::Window* KeyboardUIContent::GetKeyboardRootWindow() const {
   if (!keyboard_contents_) {
     return nullptr;
   }
   return keyboard_contents_->GetNativeView()->GetRootWindow();
 }
 
 void KeyboardUIContent::LoadContents(const GURL& url) {
   if (keyboard_contents_) {
-    content::OpenURLParams params(
-        url,
-        content::Referrer(),
-        SINGLETON_TAB,
-        ui::PAGE_TRANSITION_AUTO_TOPLEVEL,
-        false);
+    content::OpenURLParams params(url, content::Referrer(),
+                                  WindowOpenDisposition::SINGLETON_TAB,
+                                  ui::PAGE_TRANSITION_AUTO_TOPLEVEL, false);
     keyboard_contents_->OpenURL(params);
   }
 }
 
 const GURL& KeyboardUIContent::GetVirtualKeyboardUrl() {
   if (keyboard::IsInputViewEnabled()) {
     const GURL& override_url = GetOverrideContentUrl();
     return override_url.is_valid() ? override_url : default_url_;
   } else {
     return default_url_;
   }
 }
 
 bool KeyboardUIContent::ShouldEnableInsets(aura::Window* window) {
   aura::Window* keyboard_window = GetKeyboardWindow();
   return (keyboard_window->GetRootWindow() == window->GetRootWindow() &&
           keyboard::IsKeyboardOverscrollEnabled() &&
           keyboard_window->IsVisible() &&
           keyboard_controller()->keyboard_visible());
 }
 
 void KeyboardUIContent::AddBoundsChangedObserver(aura::Window* window) {
   aura::Window* target_window = window ? window->GetToplevelWindow() : nullptr;
   if (target_window)
     window_bounds_observer_->AddObservedWindow(target_window);
 }
 
 }  // namespace keyboard