Abstract WebContents/NavigationController from core TabRestore code

components/sessions/content/content_live_tab.h

Index: components/sessions/content/content_live_tab.h
diff --git a/components/sessions/content/content_live_tab.h b/components/sessions/content/content_live_tab.h
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+// Copyright (c) 2011 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 COMPONENTS_SESSIONS_CONTENT_CONTENT_LIVE_TAB_H_
+#define COMPONENTS_SESSIONS_CONTENT_CONTENT_LIVE_TAB_H_
+
+#include "base/basictypes.h"
+#include "base/supports_user_data.h"
+#include "components/sessions/content/content_serialized_navigation_builder.h"
+#include "components/sessions/core/live_tab.h"
+#include "components/sessions/sessions_export.h"
+#include "content/public/browser/web_contents.h"
+
+namespace content {
+class NavigationController;
+class NavigationEntry;
+class SessionStorageNamespace;
+}
+
+class PersistentTabRestoreServiceTest;
+
+namespace sessions {
+
+// An implementation of LiveTab that is backed by content::WebContents for use
+// on //content-based platforms.
+// Implementation note: This class can't be a WebContentsUserData due to that
+// class being unusable in the component build. crbug.com/532866
+class SESSIONS_EXPORT ContentLiveTab
+    : public LiveTab,
+      public base::SupportsUserData::Data {
+ public:
+  ~ContentLiveTab() override;
+
+  static void CreateForWebContents(content::WebContents* web_contents);
+  static ContentLiveTab* FromWebContents(content::WebContents* web_contents);
+
+  // LiveTab:
+  int GetCurrentEntryIndex() override;
+  int GetPendingEntryIndex() override;
+  sessions::SerializedNavigationEntry GetEntryAtIndex(int index) override;
+  sessions::SerializedNavigationEntry GetPendingEntry() override;
+  int GetEntryCount() override;
+  void LoadIfNecessary() override;
+  const std::string& GetUserAgentOverride() const override;
+
+  content::WebContents* web_contents() { return web_contents_; }
+  const content::WebContents* web_contents() const { return web_contents_; }
+
+ private:
+  friend class base::SupportsUserData;
+  friend class ::PersistentTabRestoreServiceTest;
+
+  explicit ContentLiveTab(content::WebContents* contents);
+
+  content::NavigationController& navigation_controller() {
+    return web_contents_->GetController();
+  }
+
+  content::WebContents* web_contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(ContentLiveTab);
+};
+
+}  // namespace sessions
+
+#endif  // COMPONENTS_SESSIONS_CONTENT_CONTENT_LIVE_TAB_H_