Avoid starting a distillation process if the URL is not distillable.

chrome/browser/dom_distiller/tab_utils.cc

 // Copyright 2014 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 "chrome/browser/dom_distiller/tab_utils.h"
 
 #include "base/message_loop/message_loop.h"
 #include "chrome/browser/dom_distiller/dom_distiller_service_factory.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h"
@@ skipping 93 matching lines @@
 void StartNavigationToDistillerViewer(content::WebContents* web_contents,
                                       const GURL& url) {
   GURL viewer_url = dom_distiller::url_utils::GetDistillerViewUrlFromUrl(
       dom_distiller::kDomDistillerScheme, url);
   content::NavigationController::LoadURLParams params(viewer_url);
   params.transition_type = ui::PAGE_TRANSITION_AUTO_BOOKMARK;
   web_contents->GetController().LoadURLWithParams(params);
 }
 
 void StartDistillation(content::WebContents* web_contents) {
+  const GURL& last_committed_url = web_contents->GetLastCommittedURL();
+  if (!dom_distiller::url_utils::IsUrlDistillable(last_committed_url)) {

[nyquist, 2015/03/13 21:21:20]

If the distillation is not started here, wouldn't it then just be started from
the navigation that has already started?

[nyquist, 2015/03/13 23:46:08]

Please remove the curly braces.

[nyquist, 2015/03/14 00:49:57]

Also; I guess at that point we would have to rename the method to
MaybeStartDistillation.

+    return;
+  }
+
   // Start distillation using |web_contents|, and ensure ViewerHandle stays
   // around until the viewer requests distillation.
   SelfDeletingRequestDelegate* view_request_delegate =
       new SelfDeletingRequestDelegate(web_contents);
   scoped_ptr<content::WebContents> old_web_contents_sptr(web_contents);
   scoped_ptr<SourcePageHandleWebContents> source_page_handle(
       new SourcePageHandleWebContents(old_web_contents_sptr.Pass()));
   DomDistillerService* dom_distiller_service =
       DomDistillerServiceFactory::GetForBrowserContext(
           web_contents->GetBrowserContext());
   scoped_ptr<DistillerPage> distiller_page =
       dom_distiller_service->CreateDefaultDistillerPageWithHandle(
                                  source_page_handle.Pass()).Pass();
 
-  const GURL& last_committed_url = web_contents->GetLastCommittedURL();
   scoped_ptr<ViewerHandle> viewer_handle = dom_distiller_service->ViewUrl(
       view_request_delegate, distiller_page.Pass(), last_committed_url);
   view_request_delegate->TakeViewerHandle(viewer_handle.Pass());
 }
 
 }  // namespace
 
 void DistillCurrentPageAndView(content::WebContents* old_web_contents) {
   DCHECK(old_web_contents);
   // Create new WebContents.
@@ skipping 12 matching lines @@
   // difficult to distinguish between the intermediate reload and a user hitting
   // the back button.
   StartNavigationToDistillerViewer(new_web_contents,
                                    old_web_contents->GetLastCommittedURL());
 
   CoreTabHelper::FromWebContents(old_web_contents)->delegate()->SwapTabContents(
       old_web_contents, new_web_contents, false, false);
 
   StartDistillation(old_web_contents);
 }