Make ClearBrowsingDataHandler only observe its own removal task

chrome/browser/browsing_data/browsing_data_remover.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 CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_
 
 #include <stdint.h>
 
 #include <queue>
@@ skipping 76 matching lines @@
 //
 //         void DeleteCookies() {
 //           remover->RemoveAndReply(Unbounded(), REMOVE_COOKIES, ALL, this);
 //         }
 //
 //         void OnBrowsingDataRemoverDone() {
 //           LOG(INFO) << "Cookies were deleted.";
 //         }
 //       }
 //
-//  3. Using an observer to report when any removal task started or all removal
-//     tasks finished (i.e. when BrowsingDataRemover changes state from idle
-//     to busy and vice versa).
-//
-//       class BrowsingDataRemoverStatusObsever {
-//         BrowsingDataRemoverStatusObserver() { remover->AddObserver(this); }
-//         ~BrowsingDataRemoverStatusObserver() {
-//           remover->RemoveObserver(this);
-//         }
-//
-//         void OnBrowsingDataRemoving(bool removing) {
-//           LOG(INFO) << "Remover is now " << (removing ? "busy" : "idle");
-//         }
-//       }
-//
 ////////////////////////////////////////////////////////////////////////////////
 
 class BrowsingDataRemover : public KeyedService
 #if defined(ENABLE_PLUGINS)
                             , public PepperFlashSettingsManager::Client
 #endif
 {
  public:
   // Mask used for Remove.
   enum RemoveDataMask {
@@ skipping 69 matching lines @@
   };
 
   struct TimeRange {
     TimeRange(base::Time begin, base::Time end) : begin(begin), end(end) {}
     bool operator==(const TimeRange& other) const;
 
     base::Time begin;
     base::Time end;
   };
 
-  // Observer is notified when the removal is active and when it's done.
-  // TODO(msramek): The semantics of the two methods are slightly different;
-  // one is called for every observer at the same time, while the other only
-  // for one observer at a time. Split the interface or deprecate
-  // OnBrowsingDataRemoving().
+  // Observer is notified when its own removal task is done.
   class Observer {
    public:
-    // NOTE: DEPRECATED; talk to dbeam/msramek before using this.
-    //
-    // Whether removal is active. Note that not having an active removal is not
-    // same as completing a removal. That is why the removing status is separate
-    // from the done message.
-    virtual void OnBrowsingDataRemoving(bool is_removing) {}
-
     // Called when a removal task is finished. Note that every removal task can
     // only have one observer attached to it, and only that one is called.
-    virtual void OnBrowsingDataRemoverDone() {}
+    virtual void OnBrowsingDataRemoverDone() = 0;
 
    protected:
     virtual ~Observer() {}
   };
 
   // The completion inhibitor can artificially delay completion of the browsing
   // data removal process. It is used during testing to simulate scenarios in
   // which the deletion stalls or takes a very long time.
   class CompletionInhibitor {
    public:
@@ skipping 354 matching lines @@
   // not initialised, so the registry must be mocked out.
   std::unique_ptr<WebappRegistry> webapp_registry_;
 #endif
 
   base::WeakPtrFactory<BrowsingDataRemover> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataRemover);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_