Improve syncing between dom distiller and the print preview request

components/dom_distiller/core/dom_distiller_service.h

Index: components/dom_distiller/core/dom_distiller_service.h
diff --git a/components/dom_distiller/core/dom_distiller_service.h b/components/dom_distiller/core/dom_distiller_service.h
index 5d2558d1142b68467f6434f8b538663a16cd7762..7e614c36693e6ca694a4bac2706d79de368f4da8 100644
--- a/components/dom_distiller/core/dom_distiller_service.h
+++ b/components/dom_distiller/core/dom_distiller_service.h
@@ -92,6 +92,10 @@ class DomDistillerServiceInterface {
       scoped_ptr<DistillerPage> distiller_page,
       const GURL& url) = 0;
 
+  virtual scoped_ptr<ViewerHandle> AddViewRequestDelegate(
+      ViewRequestDelegate* delegate,
+      const GURL& url) = 0;
+
   // Creates a default DistillerPage.
   virtual scoped_ptr<DistillerPage> CreateDefaultDistillerPage(
       const gfx::Size& render_view_size) = 0;
@@ -137,6 +141,8 @@ class DomDistillerService : public DomDistillerServiceInterface {
   scoped_ptr<ViewerHandle> ViewUrl(ViewRequestDelegate* delegate,
                                    scoped_ptr<DistillerPage> distiller_page,
                                    const GURL& url) override;
+  scoped_ptr<ViewerHandle> AddViewRequestDelegate(ViewRequestDelegate* delegate,
+                                                  const GURL& url) override;
   scoped_ptr<DistillerPage> CreateDefaultDistillerPage(
       const gfx::Size& render_view_size) override;
   scoped_ptr<DistillerPage> CreateDefaultDistillerPageWithHandle(