add a download slices table into history download db

components/history/core/browser/download_job_info.cc

Index: components/history/core/browser/download_job_info.cc
diff --git a/components/history/core/browser/download_job_info.cc b/components/history/core/browser/download_job_info.cc
new file mode 100644
index 0000000000000000000000000000000000000000..950d325dccef6845eed1a529b0b539c27f5a3d81
--- /dev/null
+++ b/components/history/core/browser/download_job_info.cc
@@ -0,0 +1,46 @@
+// Copyright (c) 2017 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.
+
+#include "components/history/core/browser/download_job_info.h"
+
+#include "components/history/core/browser/download_constants.h"
+
+namespace history {
+
+DownloadJobInfo::DownloadJobInfo()
+    : id(0),
+      start_position(0),
+      length(0),
+      received_bytes(0),
+      state(DownloadState::IN_PROGRESS),
+      interrupt_reason(0) {}
+
+DownloadJobInfo::DownloadJobInfo(DownloadId id,
+                                 int job_id,
+                                 int64_t start_position,
+                                 int64_t length,
+                                 int64_t received_bytes,
+                                 DownloadState state,
+                                 DownloadInterruptReason interrupt_reason)
+    : id(id),
+      job_id(job_id),
+      start_position(start_position),
+      length(length),
+      received_bytes(received_bytes),
+      state(state),
+      interrupt_reason(interrupt_reason) {}
+
+DownloadJobInfo::DownloadJobInfo(const DownloadJobInfo& other) = default;
+
+DownloadJobInfo::~DownloadJobInfo() = default;
+
+bool DownloadJobInfo::operator==(const DownloadJobInfo& rhs) const {
+  return id == rhs.id && job_id == rhs.job_id &&
+      start_position == rhs.start_position &&
+      length == rhs.length &&
+      received_bytes == rhs.received_bytes && state == rhs.state &&
+      interrupt_reason == rhs.interrupt_reason;
+}
+
+}  // namespace history