ntp_tiles: Avoid redundant calls to TopSites

components/ntp_tiles/most_visited_sites.cc

 // Copyright 2013 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/ntp_tiles/most_visited_sites.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 #include <utility>
@@ skipping 45 matching lines @@
     : prefs_(prefs),
       top_sites_(top_sites),
       suggestions_service_(suggestions),
       popular_sites_(std::move(popular_sites)),
       icon_cacher_(std::move(icon_cacher)),
       supervisor_(std::move(supervisor)),
       observer_(nullptr),
       num_sites_(0),
       top_sites_observer_(this),
       mv_source_(NTPTileSource::TOP_SITES),
-      weak_ptr_factory_(this) {
+      top_sites_weak_ptr_factory_(this) {
   DCHECK(prefs_);
   // top_sites_ can be null in tests.
   // TODO(sfiera): have iOS use a dummy TopSites in its tests.
   DCHECK(suggestions_service_);
   if (supervisor_)
     supervisor_->SetObserver(this);
 }
 
 MostVisitedSites::~MostVisitedSites() {
   if (supervisor_)
@@ skipping 85 matching lines @@
   // Get the current suggestions from cache. If the cache is empty, this will
   // fall back to TopSites.
   OnSuggestionsProfileAvailable(
       suggestions_service_->GetSuggestionsDataFromCache().value_or(
           SuggestionsProfile()));
 }
 
 void MostVisitedSites::InitiateTopSitesQuery() {
   if (!top_sites_)
     return;
+  if (top_sites_weak_ptr_factory_.HasWeakPtrs())
+    return;  // Ongoing query.
   top_sites_->GetMostVisitedURLs(
       base::Bind(&MostVisitedSites::OnMostVisitedURLsAvailable,
-                 weak_ptr_factory_.GetWeakPtr()),
+                 top_sites_weak_ptr_factory_.GetWeakPtr()),
       false);
 }
 
 base::FilePath MostVisitedSites::GetWhitelistLargeIconPath(const GURL& url) {
   if (supervisor_) {
     for (const auto& whitelist : supervisor_->whitelists()) {
       if (AreURLsEquivalent(whitelist.entry_point, url))
         return whitelist.large_icon_path;
     }
   }
@@ skipping 224 matching lines @@
 
 void MostVisitedSites::TopSitesChanged(TopSites* top_sites,
                                        ChangeReason change_reason) {
   if (mv_source_ == NTPTileSource::TOP_SITES) {
     // The displayed tiles are invalidated.
     InitiateTopSitesQuery();
   }
 }
 
 }  // namespace ntp_tiles