Move BrowsingDataRemoverImpl:: CompletionInhibitor to the public interface

chrome/browser/browsing_data/browsing_data_remover.h

 // Copyright 2016 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 <memory>
 #include "base/callback_forward.h"
+#include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/browsing_data/browsing_data_remover_delegate.h"
 #include "components/keyed_service/core/keyed_service.h"
 
 namespace content {
 class BrowsingDataFilterBuilder;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 152 matching lines @@
       const base::Time& delete_end,
       int remove_mask,
       int origin_type_mask,
       std::unique_ptr<content::BrowsingDataFilterBuilder> filter_builder,
       Observer* observer) = 0;
 
   // Observers.
   virtual void AddObserver(Observer* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
 
+  // A |callback| that will be called just before a deletion task is completed
+  // and observers are notified. The receiver must respond by calling
+  // |continue_to_completion| to finish the task. Used in tests to artificially
+  // prolong execution.
+  virtual void SetWouldCompleteCallbackForTesting(
+      const base::Callback<void(const base::Closure& continue_to_completion)>&
+          callback) = 0;
+
   // Parameters of the last call are exposed to be used by tests. Removal and
   // origin type masks equal to -1 mean that no removal has ever been executed.
   // TODO(msramek): If other consumers than tests are interested in this,
   // consider returning them in OnBrowsingDataRemoverDone() callback. If not,
   // consider simplifying this interface by removing these methods and changing
   // the tests to record the parameters using GMock instead.
   virtual const base::Time& GetLastUsedBeginTime() = 0;
   virtual const base::Time& GetLastUsedEndTime() = 0;
   virtual int GetLastUsedRemovalMask() = 0;
   virtual int GetLastUsedOriginTypeMask() = 0;
 };
 
 #endif // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_REMOVER_H_