Add module for counting date-last-roll-call and persisting those counts
in the user-data-dir.

BUG=590291

Review URL: https://codereview.chromium.org/1861383004

Cr-Commit-Position: refs/heads/master@{#386271}
diff --git a/components/update_client/persisted_data_unittest.cc b/components/update_client/persisted_data_unittest.cc
new file mode 100644
index 0000000..d89060f
--- /dev/null
+++ b/components/update_client/persisted_data_unittest.cc
@@ -0,0 +1,47 @@
+// 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.
+
+#include <string>
+#include <vector>
+
+#include "components/prefs/testing_pref_service.h"
+#include "components/update_client/persisted_data.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace update_client {
+
+TEST(PersistedDataTest, Simple) {
+  std::unique_ptr<TestingPrefServiceSimple> pref(
+      new TestingPrefServiceSimple());
+  PersistedData::RegisterPrefs(pref->registry());
+  std::unique_ptr<PersistedData> metadata(new PersistedData(pref.get()));
+  EXPECT_EQ(-2, metadata->GetDateLastRollCall("someappid"));
+  std::vector<std::string> items;
+  items.push_back("someappid");
+  metadata->SetDateLastRollCall(items, 3383);
+  EXPECT_EQ(3383, metadata->GetDateLastRollCall("someappid"));
+  EXPECT_EQ(-2, metadata->GetDateLastRollCall("someotherappid"));
+  metadata->SetDateLastRollCall(items, 3386);
+  EXPECT_EQ(3386, metadata->GetDateLastRollCall("someappid"));
+  EXPECT_EQ(-2, metadata->GetDateLastRollCall("someotherappid"));
+}
+
+TEST(PersistedDataTest, SharedPref) {
+  std::unique_ptr<TestingPrefServiceSimple> pref(
+      new TestingPrefServiceSimple());
+  PersistedData::RegisterPrefs(pref->registry());
+  std::unique_ptr<PersistedData> metadata(new PersistedData(pref.get()));
+  EXPECT_EQ(-2, metadata->GetDateLastRollCall("someappid"));
+  std::vector<std::string> items;
+  items.push_back("someappid");
+  metadata->SetDateLastRollCall(items, 3383);
+
+  // Now, create a new PersistedData reading from the same path, verify
+  // that it loads the value.
+  metadata.reset(new PersistedData(pref.get()));
+  EXPECT_EQ(3383, metadata->GetDateLastRollCall("someappid"));
+  EXPECT_EQ(-2, metadata->GetDateLastRollCall("someotherappid"));
+}
+
+}  // namespace update_client