[AppList] Add a Suggestions Provider to applist.

ui/app_list/search/mixer.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 "ui/app_list/search/mixer.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "ui/app_list/search_provider.h"
 #include "ui/app_list/search_result.h"
 
 namespace app_list {
 
 namespace {
 
 // Maximum number of results to show.
 const size_t kMaxResults = 6;
 const size_t kMaxMainGroupResults = 4;
 const size_t kMaxWebstoreResults = 2;
 const size_t kMaxPeopleResults = 2;
+const size_t kMaxSuggestionsResults = 6;
 
 // A value to indicate no max number of results limit.
 const size_t kNoMaxResultsLimit = 0;
 
 void UpdateResult(const SearchResult& source, SearchResult* target) {
   target->set_title(source.title());
   target->set_title_tags(source.title_tags());
   target->set_details(source.details());
   target->set_details_tags(source.details_tags());
 }
@@ skipping 85 matching lines @@
     : ui_results_(ui_results) {
 }
 Mixer::~Mixer() {
 }
 
 void Mixer::Init() {
   groups_[MAIN_GROUP].reset(new Group(kMaxMainGroupResults, 3.0));
   groups_[OMNIBOX_GROUP].reset(new Group(kNoMaxResultsLimit, 2.0));
   groups_[WEBSTORE_GROUP].reset(new Group(kMaxWebstoreResults, 1.0));
   groups_[PEOPLE_GROUP].reset(new Group(kMaxPeopleResults, 0.0));
+  groups_[SUGGESTIONS_GROUP].reset(new Group(kMaxSuggestionsResults, 3.0));
 }
 
 void Mixer::AddProviderToGroup(GroupId group, SearchProvider* provider) {
   groups_[group]->AddProvider(provider);
 }
 
 void Mixer::MixAndPublish(const KnownResults& known_results) {
   FetchResults(known_results);
 
   SortedResults results;
   results.reserve(kMaxResults);
 
   const Group& main_group = *groups_[MAIN_GROUP];
   const Group& omnibox_group = *groups_[OMNIBOX_GROUP];
   const Group& webstore_group = *groups_[WEBSTORE_GROUP];
   const Group& people_group = *groups_[PEOPLE_GROUP];
+  const Group& suggestions_group = *groups_[SUGGESTIONS_GROUP];
 
   // Adds main group and web store results first.
   results.insert(results.end(), main_group.results().begin(),
                  main_group.results().end());
   results.insert(results.end(), webstore_group.results().begin(),
                  webstore_group.results().end());
   results.insert(results.end(), people_group.results().begin(),
                  people_group.results().end());
+  results.insert(results.end(), suggestions_group.results().begin(),
+                 suggestions_group.results().end());
 
   // Collapse duplicate apps from local and web store.
   RemoveDuplicates(&results);
 
   // Fill the remaining slots with omnibox results. Always add at least one
   // omnibox result (even if there are no more slots; if we over-fill the
   // vector, the web store and people results will be removed in a later step).
   const size_t omnibox_results =
       std::min(omnibox_group.results().size(),
                results.size() < kMaxResults ? kMaxResults - results.size() : 1);
@@ skipping 77 matching lines @@
 
   results->swap(final);
 }
 
 void Mixer::FetchResults(const KnownResults& known_results) {
   for (const auto& item : groups_)
     item.second->FetchResults(known_results);
 }
 
 }  // namespace app_list