Fix handling of failed distillation.

components/dom_distiller/core/task_tracker.cc

 // Copyright 2013 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 "components/dom_distiller/core/task_tracker.h"
 
 #include "base/auto_reset.h"
 #include "base/message_loop/message_loop.h"
 #include "components/dom_distiller/core/distilled_content_store.h"
 #include "components/dom_distiller/core/proto/distilled_article.pb.h"
@@ skipping 42 matching lines @@
   distiller_->DistillPage(url,
                           distiller_page.Pass(),
                           base::Bind(&TaskTracker::OnDistillerFinished,
                                      weak_ptr_factory_.GetWeakPtr()),
                           base::Bind(&TaskTracker::OnArticleDistillationUpdated,
                                      weak_ptr_factory_.GetWeakPtr()));
 }
 
 void TaskTracker::StartBlobFetcher() {
   if (content_store_) {
+    blob_fetcher_running_ = true;
     content_store_->LoadContent(entry_,
                                 base::Bind(&TaskTracker::OnBlobFetched,
                                            weak_ptr_factory_.GetWeakPtr()));
   }
 }
 
 void TaskTracker::AddSaveCallback(const SaveCallback& callback) {
   DCHECK(!callback.is_null());
   save_callbacks_.push_back(callback);
   if (content_ready_) {
@@ skipping 67 matching lines @@
     scoped_ptr<DistilledArticleProto> distilled_article) {
   if (content_ready_) {
     return;
   }
 
   DistilledArticleReady(distilled_article.Pass());
   if (content_ready_) {
     AddDistilledContentToStore(*distilled_article_);
   }
 
+  // 'distiller_ != null' is used as a signal that distillation is in progress,
+  // so it needs to be released so that we know distillation is done.
+  base::MessageLoop::current()->DeleteSoon(FROM_HERE, distiller_.release());
+
   ContentSourceFinished();
 }
 
 void TaskTracker::CancelPendingSources() {
-  base::MessageLoop::current()->DeleteSoon(FROM_HERE, distiller_.release());
+  if (distiller_) {
+    base::MessageLoop::current()->DeleteSoon(FROM_HERE, distiller_.release());
+  }
 }
 
 void TaskTracker::OnBlobFetched(
     bool success,
     scoped_ptr<DistilledArticleProto> distilled_article) {
   blob_fetcher_running_ = false;
 
   if (content_ready_) {
     return;
   }
@@ skipping 73 matching lines @@
 void TaskTracker::AddDistilledContentToStore(
     const DistilledArticleProto& content) {
   if (content_store_) {
     content_store_->SaveContent(
         entry_, content, DistilledContentStore::SaveCallback());
   }
 }
 
 
 }  // namespace dom_distiller