Refactor and extend SnippetsBridge for multi-section support

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 "base/bind.h"
@@ skipping 75 matching lines @@
   providers_by_category_[category]->FetchSuggestionImage(suggestion_id,
                                                          callback);
 }
 
 void ContentSuggestionsService::ClearAllCachedSuggestionsForDebugging() {
   suggestions_by_category_.clear();
   id_category_map_.clear();
   for (const auto& category_provider_pair : providers_by_category_) {
     category_provider_pair.second->ClearCachedSuggestionsForDebugging(
         category_provider_pair.first);
+    FOR_EACH_OBSERVER(Observer, observers_,
+                      OnNewSuggestions(category_provider_pair.first));
   }
-  FOR_EACH_OBSERVER(Observer, observers_, OnNewSuggestions());
 }
 
 void ContentSuggestionsService::ClearCachedSuggestionsForDebugging(
     Category category) {
   for (const ContentSuggestion& suggestion :
        suggestions_by_category_[category]) {
     id_category_map_.erase(suggestion.id());
   }
   suggestions_by_category_[category].clear();
   auto iterator = providers_by_category_.find(category);
@@ skipping 82 matching lines @@
        suggestions_by_category_[category]) {
     id_category_map_.erase(suggestion.id());
   }
 
   for (const ContentSuggestion& suggestion : new_suggestions) {
     id_category_map_.insert(std::make_pair(suggestion.id(), category));
   }
 
   suggestions_by_category_[category] = std::move(new_suggestions);
 
-  FOR_EACH_OBSERVER(Observer, observers_, OnNewSuggestions());
+  FOR_EACH_OBSERVER(Observer, observers_, OnNewSuggestions(category));
 }
 
 void ContentSuggestionsService::OnCategoryStatusChanged(
     ContentSuggestionsProvider* provider,
     Category category,
     CategoryStatus new_status) {
   if (!IsCategoryStatusAvailable(new_status)) {
     for (const ContentSuggestion& suggestion :
          suggestions_by_category_[category]) {
       id_category_map_.erase(suggestion.id());
@@ skipping 36 matching lines @@
   return true;
 }
 
 void ContentSuggestionsService::NotifyCategoryStatusChanged(Category category) {
   FOR_EACH_OBSERVER(
       Observer, observers_,
       OnCategoryStatusChanged(category, GetCategoryStatus(category)));
 }
 
 }  // namespace ntp_snippets