Remove usage of DomDistillerService in ReadingListDownloadService.

ios/chrome/browser/dom_distiller/distiller_viewer.h

Index: ios/chrome/browser/dom_distiller/distiller_viewer.h
diff --git a/ios/chrome/browser/dom_distiller/distiller_viewer.h b/ios/chrome/browser/dom_distiller/distiller_viewer.h
index b4a82b37732736244914d2eb6e0e24ab0b4fa572..a67f4cad78189538585a57d9eccc73eb8e7b3541 100644
--- a/ios/chrome/browser/dom_distiller/distiller_viewer.h
+++ b/ios/chrome/browser/dom_distiller/distiller_viewer.h
@@ -17,6 +17,7 @@ class GURL;
 namespace dom_distiller {
 
 class DistilledPagePrefs;
+class Distiller;
 
 // An interface for a dom_distiller ViewRequestDelegate that distills a URL and
 // calls the given callback with the distilled HTML string and the images it
@@ -35,8 +36,7 @@ class DistillerViewerInterface : public DomDistillerRequestViewBase {
                               const std::string& title)>
       DistillationFinishedCallback;
 
-  DistillerViewerInterface(dom_distiller::DomDistillerService* distillerService,
-                           PrefService* prefs)
+  DistillerViewerInterface(PrefService* prefs)
       : DomDistillerRequestViewBase(new DistilledPagePrefs(prefs)) {}
   ~DistillerViewerInterface() override {}
 
@@ -52,29 +52,48 @@ class DistillerViewerInterface : public DomDistillerRequestViewBase {
 class DistillerViewer : public DistillerViewerInterface {
  public:
   // Creates a |DistillerView| that will be used to distill |url|.
-  // If |page| is not null, it will be used to load |url| and inject the page.
-  // If |page| is null, the default factory of |distillerService| will be used.
   // |callback| is called when distillation is finished with the protobuf
   // containing the distilled page.
   DistillerViewer(dom_distiller::DomDistillerService* distillerService,
                   PrefService* prefs,
                   const GURL& url,
-                  const DistillationFinishedCallback& callback,
-                  std::unique_ptr<dom_distiller::DistillerPage> page);
+                  const DistillationFinishedCallback& callback);
+
+  // Creates a |DistillerView| without depending on the DomDistillerService.
+  // Caller must provide |distiller_factory| and |page| which cannot be null.
+  // |callback| is called when distillation is finished with the protobuf
+  // containing the distilled page.
+  DistillerViewer(dom_distiller::DistillerFactory* distiller_factory,
+                  std::unique_ptr<dom_distiller::DistillerPage> page,
+                  PrefService* prefs,
+                  const GURL& url,
+                  const DistillationFinishedCallback& callback);
   ~DistillerViewer() override;
 
+  // DistillerViewerInterface implementation
+  // Called by the distiller service when article is ready.
   void OnArticleReady(
       const dom_distiller::DistilledArticleProto* article_proto) override;
 
   void SendJavaScript(const std::string& buffer) override;
 
  private:
+  // Called by the distiller when article is ready.
+  void OnDistillerFinished(
+      std::unique_ptr<dom_distiller::DistilledArticleProto> distilled_article);
+
+  // Called by the distiller when article is updated.
+  void OnArticleDistillationUpdated(
+      const dom_distiller::ArticleDistillationUpdate& article_update);
+
   // The url of the distilled page.
   const GURL url_;
   // JavaScript buffer.
   std::string js_buffer_;
   // Callback to run once distillation is complete.
   const DistillationFinishedCallback callback_;
+  // Keep reference of the distiller_ during distillation.
+  std::unique_ptr<Distiller> distiller_;
 
   DISALLOW_COPY_AND_ASSIGN(DistillerViewer);
 };