Remove NTP dependency on //content/...

chrome/browser/android/ntp/most_visited_sites.cc

Index: chrome/browser/android/ntp/most_visited_sites.cc
diff --git a/chrome/browser/android/ntp/most_visited_sites.cc b/chrome/browser/android/ntp/most_visited_sites.cc
index 372090f08bd8bfc924ab982ee9b9716f3ee777cc..40e1ee342604432bd6ff3a6d39f2eef9de7e7258 100644
--- a/chrome/browser/android/ntp/most_visited_sites.cc
+++ b/chrome/browser/android/ntp/most_visited_sites.cc
@@ -22,12 +22,10 @@
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
 #include "components/variations/variations_associated_data.h"
-#include "content/public/browser/browser_thread.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "ui/gfx/codec/jpeg_codec.h"
 #include "url/gurl.h"
 
-using content::BrowserThread;
 using history::TopSites;
 using suggestions::ChromeSuggestion;
 using suggestions::SuggestionsProfile;
@@ -63,10 +61,10 @@ enum MostVisitedTileType {
     NUM_TILE_TYPES,
 };
 
+// May only be called from blocking thread pool.
 std::unique_ptr<SkBitmap> MaybeFetchLocalThumbnail(
     const GURL& url,
     const scoped_refptr<TopSites>& top_sites) {
-  DCHECK_CURRENTLY_ON(BrowserThread::DB);
   scoped_refptr<base::RefCountedMemory> image;
   std::unique_ptr<SkBitmap> bitmap;
   if (top_sites && top_sites->GetPageThumbnail(url, false, &image))
@@ -169,6 +167,8 @@ MostVisitedSites::Suggestion&
 MostVisitedSites::Suggestion::operator=(Suggestion&&) = default;
 
 MostVisitedSites::MostVisitedSites(
+    scoped_refptr<base::SingleThreadTaskRunner> ui_thread,
+    scoped_refptr<base::SequencedWorkerPool> blocking_pool,
     PrefService* prefs,
     const TemplateURLService* template_url_service,
     variations::VariationsService* variations_service,
@@ -192,6 +192,8 @@ MostVisitedSites::MostVisitedSites(
       recorded_uma_(false),
       scoped_observer_(this),
       mv_source_(SUGGESTIONS_SERVICE),
+      ui_thread_(std::move(ui_thread)),
+      blocking_pool_(std::move(blocking_pool)),
       weak_ptr_factory_(this) {
   supervisor_->SetObserver(this);
 }
@@ -209,9 +211,9 @@ void MostVisitedSites::SetMostVisitedURLsObserver(Observer* observer,
   if (ShouldShowPopularSites() &&
       NeedPopularSites(prefs_, num_sites_)) {
     popular_sites_.reset(new PopularSites(
-        prefs_, template_url_service_, variations_service_, download_context_,
-        popular_sites_directory_, GetPopularSitesCountry(),
-        GetPopularSitesVersion(), false,
+        ui_thread_, blocking_pool_, prefs_, template_url_service_,
+        variations_service_, download_context_, popular_sites_directory_,
+        GetPopularSitesCountry(), GetPopularSitesVersion(), false,
         base::Bind(&MostVisitedSites::OnPopularSitesAvailable,
                    base::Unretained(this))));
   } else {
@@ -242,12 +244,14 @@ void MostVisitedSites::SetMostVisitedURLsObserver(Observer* observer,
 
 void MostVisitedSites::GetURLThumbnail(const GURL& url,
                                        const ThumbnailCallback& callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_thread_->BelongsToCurrentThread());
 
-  // TODO(treib): Move this to the blocking pool? Doesn't seem related to DB.
-  BrowserThread::PostTaskAndReplyWithResult(
-      BrowserThread::DB, FROM_HERE,
-      base::Bind(&MaybeFetchLocalThumbnail, url, top_sites_),
+  base::PostTaskAndReplyWithResult(
+      blocking_pool_
+          ->GetTaskRunnerWithShutdownBehavior(
+              base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN)
+          .get(),
+      FROM_HERE, base::Bind(&MaybeFetchLocalThumbnail, url, top_sites_),
       base::Bind(&MostVisitedSites::OnLocalThumbnailFetched,
                  weak_ptr_factory_.GetWeakPtr(), url, callback));
 }
@@ -256,7 +260,7 @@ void MostVisitedSites::OnLocalThumbnailFetched(
     const GURL& url,
     const ThumbnailCallback& callback,
     std::unique_ptr<SkBitmap> bitmap) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_thread_->BelongsToCurrentThread());
   if (!bitmap.get()) {
     // A thumbnail is not locally available for |url|. Make sure it is put in
     // the list to be fetched at the next visit to this site.
@@ -289,7 +293,7 @@ void MostVisitedSites::OnObtainedThumbnail(bool is_local_thumbnail,
                                            const ThumbnailCallback& callback,
                                            const GURL& url,
                                            const SkBitmap* bitmap) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(ui_thread_->BelongsToCurrentThread());
   callback.Run(is_local_thumbnail, bitmap);
 }