Adds an experiment that enabled SuggestionsService suggestions (MostLikely) on LocalNTP

chrome/browser/search/instant_service.cc

Index: chrome/browser/search/instant_service.cc
diff --git a/chrome/browser/search/instant_service.cc b/chrome/browser/search/instant_service.cc
index 5f668effb17431b5f644491abaeffea26079ed2a..c8ad4e877eff148cffba01601ea8522175aba327 100644
--- a/chrome/browser/search/instant_service.cc
+++ b/chrome/browser/search/instant_service.cc
@@ -4,6 +4,8 @@
 
 #include "chrome/browser/search/instant_service.h"
 
+#include "base/metrics/field_trial.h"
+#include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/favicon/fallback_icon_service_factory.h"
 #include "chrome/browser/favicon/large_icon_service_factory.h"
@@ -13,6 +15,7 @@
 #include "chrome/browser/search/instant_service_observer.h"
 #include "chrome/browser/search/most_visited_iframe_source.h"
 #include "chrome/browser/search/search.h"
+#include "chrome/browser/search/suggestions/suggestions_service_factory.h"
 #include "chrome/browser/search/suggestions/suggestions_source.h"
 #include "chrome/browser/search/thumbnail_source.h"
 #include "chrome/browser/search_engines/template_url_service_factory.h"
@@ -29,6 +32,8 @@
 #include "components/history/core/browser/top_sites.h"
 #include "components/keyed_service/core/service_access_type.h"
 #include "components/search_engines/template_url_service.h"
+#include "components/suggestions/proto/suggestions.pb.h"
+#include "components/suggestions/suggestions_service.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
@@ -53,7 +58,8 @@ InstantService::InstantService(Profile* profile)
     : profile_(profile),
       template_url_service_(TemplateURLServiceFactory::GetForProfile(profile_)),
       omnibox_start_margin_(chrome::kDisableStartMargin),
-      weak_ptr_factory_(this) {
+      weak_ptr_factory_(this),
+      suggestions_service(NULL) {
   // The initialization below depends on a typical set of browser threads. Skip
   // it if we are running in a unit test without the full suite.
   if (!content::BrowserThread::CurrentlyOn(content::BrowserThread::UI))
@@ -130,6 +136,22 @@ InstantService::InstantService(Profile* profile)
   content::URLDataSource::Add(profile_, new MostVisitedIframeSource());
   content::URLDataSource::Add(
       profile_, new suggestions::SuggestionsSource(profile_));
+
+  if (base::StartsWith(
+          base::FieldTrialList::FindFullName("LocalNTPSuggestionsService"),
+          "Enabled", base::CompareCase::INSENSITIVE_ASCII)) {
+    suggestions_service =
+        suggestions::SuggestionsServiceFactory::GetForProfile(profile_);
+  }
+
+  if (suggestions_service) {
+    suggestions::SuggestionsService* if (suggestions_service) {

[kmadhusu, 2015/07/29 17:42:31]

Can you please explain this code? Why do you need
"suggestions::SuggestionsService* " before an if statement?

[fserb, 2015/07/29 19:02:59]

I messed up the last comment fix. :) thanks. done.

+      suggestions_service->FetchSuggestionsData(
+          suggestions::INITIALIZED_ENABLED_HISTORY,
+          base::Bind(&InstantService::OnSuggestionsAvailable,
+                     weak_ptr_factory_.GetWeakPtr()));
+    }
+  }
 }
 
 InstantService::~InstantService() {
@@ -167,6 +189,12 @@ void InstantService::DeleteMostVisitedItem(const GURL& url) {
     return;
 
   top_sites->AddBlacklistedURL(url);
+  if (suggestions_service) {
+    suggestions_service->BlacklistURL(
+        url, base::Bind(&InstantService::OnSuggestionsAvailable,

[kmadhusu, 2015/07/29 17:42:31]

Instead of passing a callback as an argument, have you considered implementing
SuggestionServiceObserver something similar to TopSitesObserver?

[fserb, 2015/07/29 19:03:00]

SuggestionsService has a callback model, it doesn't expose an observer.

[kmadhusu, 2015/07/30 21:57:02]

(My 2 cents) Hmm. I am not entirely convinced by the callback model. I don't
know the rationale behind the original model. InstantService should not worry
about suggestions_service->BlacklistURL() response success/failure.
InstantService should just notify SuggestionService about the new black list url
and SuggestionService should notify the corresponding observers about this. Git
blame says that mathp@ modified/wrote most of the suggestions_service. Please
discuss with mathp@ and consider adding an observer model in the future.

+                        weak_ptr_factory_.GetWeakPtr()),
+        base::Closure());
+  }
 }
 
 void InstantService::UndoMostVisitedDeletion(const GURL& url) {
@@ -176,6 +204,12 @@ void InstantService::UndoMostVisitedDeletion(const GURL& url) {
     return;
 
   top_sites->RemoveBlacklistedURL(url);
+  if (suggestions_service) {
+    suggestions_service->UndoBlacklistURL(
+        url, base::Bind(&InstantService::OnSuggestionsAvailable,
+                        weak_ptr_factory_.GetWeakPtr()),
+        base::Closure());
+  }
 }
 
 void InstantService::UndoAllMostVisitedDeletions() {
@@ -185,6 +219,11 @@ void InstantService::UndoAllMostVisitedDeletions() {
     return;
 
   top_sites->ClearBlacklistedURLs();
+  if (suggestions_service) {
+    suggestions_service->ClearBlacklist(
+        base::Bind(&InstantService::OnSuggestionsAvailable,
+                   weak_ptr_factory_.GetWeakPtr()));
+  }
 }
 
 void InstantService::UpdateThemeInfo() {
@@ -265,6 +304,23 @@ void InstantService::OnRendererProcessTerminated(int process_id) {
   }
 }
 
+void InstantService::OnSuggestionsAvailable(
+    const suggestions::SuggestionsProfile& profile) {
+  std::vector<InstantMostVisitedItem> new_suggestions_items;
+  for (int i = 0; i < profile.suggestions_size(); ++i) {
+    const suggestions::ChromeSuggestion& suggestion = profile.suggestions(i);
+
+    InstantMostVisitedItem item;
+    item.url = GURL(suggestion.url());
+    item.title = base::UTF8ToUTF16(suggestion.title());
+    item.thumbnail = GURL(suggestion.thumbnail());
+    item.favicon = GURL(suggestion.favicon_url());
+    new_suggestions_items.push_back(item);
+  }
+  suggestions_items_ = new_suggestions_items;
+  NotifyAboutMostVisitedItems();
+}
+
 void InstantService::OnMostVisitedItemsReceived(
     const history::MostVisitedURLList& data) {
   history::MostVisitedURLList reordered_data(data);
@@ -282,8 +338,13 @@ void InstantService::OnMostVisitedItemsReceived(
 }
 
 void InstantService::NotifyAboutMostVisitedItems() {
-  FOR_EACH_OBSERVER(InstantServiceObserver, observers_,
-                    MostVisitedItemsChanged(most_visited_items_));
+  if (suggestions_service && !suggestions_items_.empty()) {
+    FOR_EACH_OBSERVER(InstantServiceObserver, observers_,
+                      MostVisitedItemsChanged(suggestions_items_));
+  } else {
+    FOR_EACH_OBSERVER(InstantServiceObserver, observers_,
+                      MostVisitedItemsChanged(most_visited_items_));
+  }
 }
 
 #if defined(ENABLE_THEMES)