FBTF: Move the TabRestoreService::Observer into its own file.

chrome/browser/jumplist_win.h

Index: chrome/browser/jumplist_win.h
diff --git a/chrome/browser/jumplist_win.h b/chrome/browser/jumplist_win.h
index e85735db5663efdfd79872efc9af9eeb23691bbb..58146d04c5122b07e9d9d3ce31c6f99bf8d9e891 100644
--- a/chrome/browser/jumplist_win.h
+++ b/chrome/browser/jumplist_win.h
@@ -15,6 +15,7 @@
 #include "chrome/browser/cancelable_request.h"
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
+#include "chrome/browser/sessions/tab_restore_service_observer.h"
 
 class FilePath;
 class Profile;
@@ -91,7 +92,7 @@ typedef std::vector<scoped_refptr<ShellLinkItem> > ShellLinkItemList;
 // * Creatng COM objects used by JumpList from PageUsageData objects;
 // * Adding COM objects to JumpList, etc.
 //
-// This class also implements TabRestoreService::Observer. So, once we call
+// This class also implements TabRestoreServiceObserver. So, once we call
 // AddObserver() and register this class as an observer, it automatically
 // updates a JumpList when a tab is added or removed.
 //
@@ -99,7 +100,7 @@ typedef std::vector<scoped_refptr<ShellLinkItem> > ShellLinkItemList;
 // update it in a UI thread. To solve this problem, this class posts a
 // task when it actually updates a JumpList. (This task is implemented in an
 // anomynous namespace in "jumplist_win.cc".)
-class JumpList : public TabRestoreService::Observer {
+class JumpList : public TabRestoreServiceObserver {
  public:
   JumpList();
   ~JumpList();