Upstream oodles of Chrome for Android code into Chromium.

chrome/browser/android/history_report/delta_file_service.h

Index: chrome/browser/android/history_report/delta_file_service.h
diff --git a/chrome/browser/android/history_report/delta_file_service.h b/chrome/browser/android/history_report/delta_file_service.h
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+// 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 CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_SERVICE_H_
+#define CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_SERVICE_H_
+
+#include <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/sequenced_worker_pool.h"
+
+class GURL;
+
+namespace base {
+class FilePath;
+}  // namespace base
+
+namespace history_report {
+
+class DeltaFileEntryWithData;
+class DeltaFileBackend;
+
+// Delta file for gmscore integration and history reporting.
+class DeltaFileService {
+ public:
+  explicit DeltaFileService(const base::FilePath& dir);
+  ~DeltaFileService();
+
+  // Adds new addtion entry to delta file.
+  void PageAdded(const GURL& url);
+  // Adds new deletion entry to delta file.
+  void PageDeleted(const GURL& url);
+  // Removes all delta file entries with seqno <= lower_bound.
+  // Returns max seqno in delta file.
+  int64 Trim(int64 lower_bound);
+  // Removes all data from delta file and populates it with new addition
+  // entries for given urls.
+  bool Recreate(const std::vector<std::string>& urls);
+  // Provides up to limit delta file entries with seqno > last_seq_no.
+  scoped_ptr<std::vector<DeltaFileEntryWithData> > Query(int64 last_seq_no,
+                                                         int32 limit);
+  // Removes all entries from delta file.
+  void Clear();
+
+  // Dumps internal state to string.
+  std::string Dump();
+
+ private:
+
+  base::SequencedWorkerPool::SequenceToken worker_pool_token_;
+  scoped_ptr<DeltaFileBackend> delta_file_backend_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeltaFileService);
+};
+
+}  // namespace history_report
+
+#endif  // CHROME_BROWSER_ANDROID_HISTORY_REPORT_DELTA_FILE_SERVICE_H_