Navigation: move RestoreType and ReloadType into a separate file

content/public/browser/navigation_type.h

-// 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.
-
-#ifndef CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_
-#define CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_
-
-namespace content {
-
-// Indicates different types of navigations that can occur that we will handle
-// separately.
-enum NavigationType {
-  // Unknown type.
-  NAVIGATION_TYPE_UNKNOWN,
-
-  // A new page was navigated to in the main frame. This covers all cases where
-  // the main frame navigated and a new navigation entry was created. This means
-  // cases like navigations to a hash on the same page are NEW_PAGE, not
-  // IN_PAGE. (Navigation entries created by subframe navigations are
-  // NEW_SUBFRAME.)
-  NAVIGATION_TYPE_NEW_PAGE,
-
-  // Renavigating to an existing navigation entry. This is the case for history
-  // navigation, reloads, and location.replace().
-  NAVIGATION_TYPE_EXISTING_PAGE,
-
-  // The same page has been reloaded as a result of the user requesting
-  // navigation to that same page (like pressing Enter in the URL bar). This
-  // is not the same as an in-page navigation because we'll actually have a
-  // pending entry for the load, which is then meaningless.
-  NAVIGATION_TYPE_SAME_PAGE,
-
-  // A new subframe was manually navigated by the user. We will create a new
-  // NavigationEntry so they can go back to the previous subframe content
-  // using the back button.
-  NAVIGATION_TYPE_NEW_SUBFRAME,
-
-  // A subframe in the page was automatically loaded or navigated to such that
-  // a new navigation entry should not be created. There are two cases:
-  //  1. Stuff like iframes containing ads that the page loads automatically.
-  //     The user doesn't want to see these, so we just update the existing
-  //     navigation entry.
-  //  2. Going back/forward to previous subframe navigations. We don't create
-  //     a new entry here either, just update the last committed entry.
-  // These two cases are actually pretty different, they just happen to
-  // require almost the same code to handle.
-  NAVIGATION_TYPE_AUTO_SUBFRAME,
-
-  // Nothing happened. This happens when we get information about a page we
-  // don't know anything about. It can also happen when an iframe in a popup
-  // navigated to about:blank is navigated. Nothing needs to be done.
-  NAVIGATION_TYPE_NAV_IGNORE,
-};
-
-}  // namespace content
-
-#endif  // CONTENT_PUBLIC_BROWSER_NAVIGATION_TYPE_H_