Ntp: show AllDismissedItem when all sections have been dismissed.

components/ntp_snippets/content_suggestions_service.cc

 // 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 "components/ntp_snippets/content_suggestions_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 #include <utility>
@@ skipping 132 matching lines @@
   DCHECK(removed) << "The dismissed suggestion " << suggestion_id
                   << " has already been removed. Providers must not call"
                   << " OnNewSuggestions in response to DismissSuggestion.";
 }
 
 void ContentSuggestionsService::DismissCategory(Category category) {
   auto providers_it = providers_by_category_.find(category);
   if (providers_it == providers_by_category_.end())
     return;
 
+  suggestions_by_category_[category].clear();
+  dismissed_providers_by_category_[providers_it->first] = providers_it->second;
   providers_by_category_.erase(providers_it);
   categories_.erase(
       std::find(categories_.begin(), categories_.end(), category));
 }
 
+void ContentSuggestionsService::RestoreDismissedCategories() {
+  // Make a copy as the original will be modified during iteration.
+  auto dismissed_providers_by_category_copy = dismissed_providers_by_category_;
+  for (const auto& category_provider_pair :
+       dismissed_providers_by_category_copy) {
+    RegisterCategoryIfRequired(category_provider_pair.second,
+                               category_provider_pair.first);
+  }
+  DCHECK(dismissed_providers_by_category_.empty());
+}
+
 void ContentSuggestionsService::AddObserver(Observer* observer) {
   observers_.AddObserver(observer);
 }
 
 void ContentSuggestionsService::RemoveObserver(Observer* observer) {
   observers_.RemoveObserver(observer);
 }
 
 void ContentSuggestionsService::RegisterProvider(
     std::unique_ptr<ContentSuggestionsProvider> provider) {
@@ skipping 99 matching lines @@
 
 bool ContentSuggestionsService::RegisterCategoryIfRequired(
     ContentSuggestionsProvider* provider,
     Category category) {
   auto it = providers_by_category_.find(category);
   if (it != providers_by_category_.end()) {
     DCHECK_EQ(it->second, provider);
     return false;
   }
 
+  auto dismissed_it = dismissed_providers_by_category_.find(category);
+  if (dismissed_it != dismissed_providers_by_category_.end()) {
+    DCHECK_EQ(dismissed_it->second, provider);
+    dismissed_providers_by_category_.erase(dismissed_it);
+  }
+
   providers_by_category_[category] = provider;
   categories_.push_back(category);
   SortCategories();
   if (IsCategoryStatusAvailable(provider->GetCategoryStatus(category))) {
     suggestions_by_category_.insert(
         std::make_pair(category, std::vector<ContentSuggestion>()));
   }
   return true;
 }
 
@@ skipping 38 matching lines @@
           if (left.IsKnownCategory(KnownCategories::BOOKMARKS))
             return false;
           if (right.IsKnownCategory(KnownCategories::BOOKMARKS))
             return true;
         }
         return category_factory_.CompareCategories(left, right);
       });
 }
 
 }  // namespace ntp_snippets