NTP: Correct the add shortcut button status when no custom link

Update page most visited info when there is no custom link

When you Toggle Most visited sites
(InstantService::ToggleMostVisitedOrCustomLinks), the change will not
be notified to the page if there is no custom link.

The add shortcut button status will not be correct.

Bug: 1161688
Change-Id: Ia18355afc4686aa881d5c0c57b8a7e8bb97925de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2612334
Commit-Queue: Esmael Elmoslimany <aee@chromium.org>
Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842658}

AUTHORS

@@ -1088,6 +1088,7 @@ Waihung Fu <fufranci@amazon.com>
 Wojciech Bielawski <wojciech.bielawski@gmail.com>
 Wanming Lin <wanming.lin@intel.com>
 Wei Li <wei.c.li@intel.com>
+Wen Fan <fanwen1@huawei.com>
 Wenxiang Qian <leonwxqian@gmail.com>
 WenSheng He <wensheng.he@samsung.com>
 Wesley Lancel <wesleylancel@gmail.com>

chrome/browser/search/instant_service.cc

@@ -375,7 +375,10 @@ bool InstantService::ToggleMostVisitedOrCustomLinks() {
   // user has never customized their shortcuts.
   //
   // For more details, see custom_links_mananger.h and most_visited_sites.h.
-  if (!was_initialized && !most_visited_sites_->IsCustomLinksInitialized()) {
+  if ((!was_initialized && !most_visited_sites_->IsCustomLinksInitialized()) ||
+      // Ensure that the add shortcut button status is correct when there is no
+      // custom link.
+      most_visited_sites_->GetCustomLinkNum() == 0) {
     NotifyAboutMostVisitedInfo();
   }
 

components/ntp_tiles/most_visited_sites.cc

@@ -392,6 +392,10 @@ void MostVisitedSites::UndoCustomLinkAction() {
     BuildCurrentTiles();
 }
 
+size_t MostVisitedSites::GetCustomLinkNum() {
+  return custom_links_->GetLinks().size();
+}
+
 void MostVisitedSites::AddOrRemoveBlockedUrl(const GURL& url, bool add_url) {
   if (add_url) {
     base::RecordAction(base::UserMetricsAction("Suggestions.Site.Removed"));

components/ntp_tiles/most_visited_sites.h

@@ -215,6 +215,8 @@ class MostVisitedSites : public history::TopSitesObserver,
   // must be enabled.
   void UndoCustomLinkAction();
 
+  size_t GetCustomLinkNum();
+
   void AddOrRemoveBlockedUrl(const GURL& url, bool add_url);
   void ClearBlockedUrls();