Remove old session history logic.

content/renderer/history_controller.h

-// Copyright 2014 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.
-
-/*
- * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
- * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
- *     (http://www.torchmobile.com/)
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1.  Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- * 2.  Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef CONTENT_RENDERER_HISTORY_CONTROLLER_H_
-#define CONTENT_RENDERER_HISTORY_CONTROLLER_H_
-
-#include <memory>
-#include <utility>
-
-#include "base/containers/hash_tables.h"
-#include "base/macros.h"
-#include "content/common/content_export.h"
-#include "content/renderer/history_entry.h"
-#include "third_party/WebKit/public/web/WebHistoryCommitType.h"
-#include "third_party/WebKit/public/web/WebHistoryItem.h"
-
-namespace blink {
-class WebFrame;
-class WebLocalFrame;
-enum class WebCachePolicy;
-}
-
-namespace content {
-class RenderFrameImpl;
-class RenderViewImpl;
-struct NavigationParams;
-
-// A guide to history state in the renderer:
-//
-// HistoryController: Owned by RenderView, is the entry point for interacting
-//     with history. Handles most of the operations to modify history state,
-//     navigate to an existing back/forward entry, etc.
-//
-// HistoryEntry: Represents a single entry in the back/forward list,
-//     encapsulating all frames in the page it represents. It provides access
-//     to each frame's state via lookups by frame id or frame name.
-// HistoryNode: Represents a single frame in a HistoryEntry. Owned by a
-//     HistoryEntry. HistoryNodes form a tree that mirrors the frame tree in
-//     the corresponding page.
-// HistoryNodes represent the structure of the page, but don't hold any
-// per-frame state except a list of child frames.
-// WebHistoryItem (lives in blink): The state for a given frame. Can persist
-//     across navigations. WebHistoryItem is reference counted, and each
-//     HistoryNode holds a reference to its single corresponding
-//     WebHistoryItem. Can be referenced by multiple HistoryNodes and can
-//     therefore exist in multiple HistoryEntry instances.
-//
-// Suppose we have the following page, foo.com, which embeds foo.com/a in an
-// iframe:
-//
-// HistoryEntry 0:
-//     HistoryNode 0_0 (WebHistoryItem A (url: foo.com))
-//         HistoryNode 0_1: (WebHistoryItem B (url: foo.com/a))
-//
-// Now we navigate the top frame to bar.com, which embeds bar.com/b and
-// bar.com/c in iframes, and bar.com/b in turn embeds bar.com/d. We will
-// create a new HistoryEntry with a tree containing 4 new HistoryNodes. The
-// state will be:
-//
-// HistoryEntry 1:
-//     HistoryNode 1_0 (WebHistoryItem C (url: bar.com))
-//         HistoryNode 1_1: (WebHistoryItem D (url: bar.com/b))
-//             HistoryNode 1_3: (WebHistoryItem F (url: bar.com/d))
-//         HistoryNode 1_2: (WebHistoryItem E (url: bar.com/c))
-//
-//
-// Finally, we navigate the first subframe from bar.com/b to bar.com/e, which
-// embeds bar.com/f. We will create a new HistoryEntry and new HistoryNode for
-// each frame. Any frame that navigates (bar.com/e and its child, bar.com/f)
-// will receive a new WebHistoryItem. However, 2 frames were not navigated
-// (bar.com and bar.com/c), so those two frames will reuse the existing
-// WebHistoryItem:
-//
-// HistoryEntry 2:
-//     HistoryNode 2_0 (WebHistoryItem C (url: bar.com))  *REUSED*
-//         HistoryNode 2_1: (WebHistoryItem G (url: bar.com/e))
-//            HistoryNode 2_3: (WebHistoryItem H (url: bar.com/f))
-//         HistoryNode 2_2: (WebHistoryItem E (url: bar.com/c)) *REUSED*
-//
-class CONTENT_EXPORT HistoryController {
- public:
-  explicit HistoryController(RenderViewImpl* render_view);
-  ~HistoryController();
-
-  void set_provisional_entry(std::unique_ptr<HistoryEntry> entry) {
-    provisional_entry_ = std::move(entry);
-  }
-
-  // Return true if the main frame ended up loading a request as part of the
-  // history navigation.
-  bool GoToEntry(blink::WebLocalFrame* main_frame,
-                 std::unique_ptr<HistoryEntry> entry,
-                 std::unique_ptr<NavigationParams> navigation_params,
-                 blink::WebCachePolicy cache_policy);
-
-  void UpdateForCommit(RenderFrameImpl* frame,
-                       const blink::WebHistoryItem& item,
-                       blink::WebHistoryCommitType commit_type,
-                       bool navigation_within_page);
-
-  HistoryEntry* GetCurrentEntry();
-  blink::WebHistoryItem GetItemForNewChildFrame(RenderFrameImpl* frame) const;
-  void RemoveChildrenForRedirect(RenderFrameImpl* frame);
-
- private:
-  typedef std::vector<std::pair<blink::WebFrame*, blink::WebHistoryItem> >
-      HistoryFrameLoadVector;
-  void RecursiveGoToEntry(blink::WebFrame* frame,
-                          HistoryFrameLoadVector& sameDocumentLoads,
-                          HistoryFrameLoadVector& differentDocumentLoads);
-
-  void UpdateForInitialLoadInChildFrame(RenderFrameImpl* frame,
-                                        const blink::WebHistoryItem& item);
-  void CreateNewBackForwardItem(RenderFrameImpl* frame,
-                                const blink::WebHistoryItem& item,
-                                bool clone_children_of_target);
-
-  RenderViewImpl* render_view_;
-
-  // A HistoryEntry representing the currently-loaded page.
-  std::unique_ptr<HistoryEntry> current_entry_;
-  // A HistoryEntry representing the page that is being loaded, or an empty
-  // scoped_ptr if no page is being loaded.
-  std::unique_ptr<HistoryEntry> provisional_entry_;
-
-  // The NavigationParams corresponding to the last back/forward load that was
-  // initiated by |GoToEntry|. This is kept around so that it can be passed into
-  // existing frames affected by a history navigation in GoToEntry(), and can be
-  // passed into frames created after the commit that resulted from the
-  // navigation in GetItemForNewChildFrame().
-  //
-  // This is reset in UpdateForCommit if we see a commit from a different
-  // navigation, to avoid using stale parameters.
-  std::unique_ptr<NavigationParams> navigation_params_;
-
-  DISALLOW_COPY_AND_ASSIGN(HistoryController);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_HISTORY_CONTROLLER_H_