[sync] WebContentsObserver based sessions notifications

chrome/browser/sync/glue/synced_tab_delegate_android.h

 // Copyright 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.
 
 #ifndef CHROME_BROWSER_SYNC_GLUE_SYNCED_TAB_DELEGATE_ANDROID_H_
 #define CHROME_BROWSER_SYNC_GLUE_SYNCED_TAB_DELEGATE_ANDROID_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 17 matching lines @@
 // a method to set web contents later when tab is brought to memory.
 class SyncedTabDelegateAndroid : public sync_sessions::SyncedTabDelegate {
  public:
   explicit SyncedTabDelegateAndroid(TabAndroid* owning_tab_);
   ~SyncedTabDelegateAndroid() override;
 
   // SyncedTabDelegate:
   SessionID::id_type GetWindowId() const override;
   SessionID::id_type GetSessionId() const override;
   bool IsBeingDestroyed() const override;
+  SessionID::id_type GetSourceTabID() const override;
   std::string GetExtensionAppId() const override;
   bool IsInitialBlankNavigation() const override;
   int GetCurrentEntryIndex() const override;
   int GetEntryCount() const override;
   GURL GetVirtualURLAtIndex(int i) const override;
   GURL GetFaviconURLAtIndex(int i) const override;
   ui::PageTransition GetTransitionAtIndex(int i) const override;
   void GetSerializedNavigationAtIndex(
       int i,
       sessions::SerializedNavigationEntry* serialized_entry) const override;
@@ skipping 14 matching lines @@
  private:
   content::WebContents* web_contents_;
   TabAndroid* tab_android_;
   TabContentsSyncedTabDelegate* tab_contents_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncedTabDelegateAndroid);
 };
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_SYNCED_TAB_DELEGATE_ANDROID_H_