1 files changed, 120 insertions, 0 deletions
diff --git a/chromium/components/browsing_data/core/counters/browsing_data_counter.h b/chromium/components/browsing_data/core/counters/browsing_data_counter.h
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+++ b/chromium/components/browsing_data/core/counters/browsing_data_counter.h
@@ -0,0 +1,120 @@
+// Copyright 2015 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_BROWSING_DATA_CORE_COUNTERS_BROWSING_DATA_COUNTER_H_
+#define COMPONENTS_BROWSING_DATA_CORE_COUNTERS_BROWSING_DATA_COUNTER_H_
+
+#include <stdint.h>
+#include <string>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "components/prefs/pref_member.h"
+
+class PrefService;
+
+namespace browsing_data {
+
+class BrowsingDataCounter {
+ public:
+  typedef int64_t ResultInt;
+
+  // Base class of results returned by BrowsingDataCounter. When the computation
+  // has started, an instance is returned to represent a pending result.
+  class Result {
+   public:
+    explicit Result(const BrowsingDataCounter* source);
+    virtual ~Result();
+
+    const BrowsingDataCounter* source() const { return source_; }
+    virtual bool Finished() const;
+
+   private:
+    const BrowsingDataCounter* source_;
+
+    DISALLOW_COPY_AND_ASSIGN(Result);
+  };
+
+  // A subclass of Result returned when the computation has finished. The result
+  // value can be retrieved by calling |Value()|. Some BrowsingDataCounter
+  // subclasses might use a subclass of FinishedResult to provide more complex
+  // results.
+  class FinishedResult : public Result {
+   public:
+    FinishedResult(const BrowsingDataCounter* source, ResultInt value);
+    ~FinishedResult() override;
+
+    // Result:
+    bool Finished() const override;
+
+    ResultInt Value() const;
+
+   private:
+    ResultInt value_;
+
+    DISALLOW_COPY_AND_ASSIGN(FinishedResult);
+  };
+
+  typedef base::Callback<void(std::unique_ptr<Result>)> Callback;
+
+  BrowsingDataCounter();
+  virtual ~BrowsingDataCounter();
+
+  // Should be called once to initialize this class.
+  void Init(PrefService* pref_service, const Callback& callback);
+
+  // Name of the preference associated with this counter.
+  virtual const char* GetPrefName() const = 0;
+
+  // PrefService that manages the preferences for the user profile
+  // associated with this counter.
+  PrefService* GetPrefs() const;
+
+  // Restarts the counter. Will be called automatically if the counting needs
+  // to be restarted, e.g. when the deletion preference changes state or when
+  // we are notified of data changes.
+  void Restart();
+
+ protected:
+  // Should be called from |Count| by any overriding class to indicate that
+  // counting is finished and report |value| as the result.
+  void ReportResult(ResultInt value);
+
+  // A convenience overload of the previous method that allows subclasses to
+  // provide a custom |result|.
+  void ReportResult(std::unique_ptr<Result> result);
+
+  // Calculates the beginning of the counting period as |period_| before now.
+  base::Time GetPeriodStart();
+
+ private:
+  // Called after the class is initialized by calling |Init|.
+  virtual void OnInitialized();
+
+  // Count the data.
+  virtual void Count() = 0;
+
+  // Pointer to the PrefService that manages the preferences for the user
+  // profile associated with this counter.
+  PrefService* pref_service_;
+
+  // The callback that will be called when the UI should be updated with a new
+  // counter value.
+  Callback callback_;
+
+  // The boolean preference indicating whether this data type is to be deleted.
+  // If false, we will not count it.
+  BooleanPrefMember pref_;
+
+  // The integer preference describing the time period for which this data type
+  // is to be deleted.
+  IntegerPrefMember period_;
+
+  // Whether this class was properly initialized by calling |Init|.
+  bool initialized_ = false;
+};
+
+}  // namespace browsing_data
+
+#endif  // COMPONENTS_BROWSING_DATA_CORE_COUNTERS_BROWSING_DATA_COUNTER_H_