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

chrome/browser/dom_distiller/tab_utils.cc

Index: chrome/browser/dom_distiller/tab_utils.cc
diff --git a/chrome/browser/dom_distiller/tab_utils.cc b/chrome/browser/dom_distiller/tab_utils.cc
index c288d909129f8ea72516bf60ad52064a7553f49c..1c583401a25222a3240d0fb3d88826a236869dab 100644
--- a/chrome/browser/dom_distiller/tab_utils.cc
+++ b/chrome/browser/dom_distiller/tab_utils.cc
@@ -111,6 +111,11 @@ void StartNavigationToDistillerViewer(content::WebContents* web_contents,
 }
 
 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 =
@@ -125,7 +130,6 @@ void StartDistillation(content::WebContents* web_contents) {
       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());