Cancel the JumpList update if top 5 most visited URLs are unchanged

chrome/browser/win/jumplist_update_util.cc

Index: chrome/browser/win/jumplist_update_util.cc
diff --git a/chrome/browser/win/jumplist_update_util.cc b/chrome/browser/win/jumplist_update_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..da47fd0c700ca629178671b3bb35362b70021223
--- /dev/null
+++ b/chrome/browser/win/jumplist_update_util.cc
@@ -0,0 +1,26 @@
+// 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 <algorithm>
+#include <iterator>
+
+#include "chrome/browser/win/jumplist_update_util.h"

[grt (UTC plus 2), 2017/05/30 08:51:41]

nit: move up above other includes
(https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes)

[chengx, 2017/05/30 19:37:02]

Done.

+
+bool MostVisitedItemsUnchanged(const ShellLinkItemList& items,
+                               const history::MostVisitedURLList& urls,
+                               size_t most_visited_items) {

[grt (UTC plus 2), 2017/05/30 08:51:41]

nit: max_item_count?

[chengx, 2017/05/30 19:37:02]

Done.

+  // If the number of urls going to be displayed doesn't equal to the current
+  // one, the most visited items are considered to have changes.
+  // Otherwise, check if the current urls stored in |items| equal to the first
+  // |most_visited_items| urls in |urls| to determine if the most visited items
+  // are changed or not.
+
+  if (size_t(std::min(urls.size(), most_visited_items)) != items.size())

[grt (UTC plus 2), 2017/05/30 08:51:41]

urls.size() and most_visited_items are both size_t. why is the cast necessary?

[chengx, 2017/05/30 19:37:02]

Yes, it should be removed.

+    return false;
+
+  return std::equal(std::begin(items), std::end(items), std::begin(urls),
+                    [](const auto& item_ptr, const auto& most_visited_url) {
+                      return item_ptr->url() == most_visited_url.url.spec();
+                    });
+}