Add a DistilledContentStore (and an in-memory impl)

components/dom_distiller/core/task_tracker.cc

Index: components/dom_distiller/core/task_tracker.cc
diff --git a/components/dom_distiller/core/task_tracker.cc b/components/dom_distiller/core/task_tracker.cc
index 5dd17d3a598b6976caabd263374948ae3f358c58..c6829897e9a974d735747c9c9e823b86bc4fb32a 100644
--- a/components/dom_distiller/core/task_tracker.cc
+++ b/components/dom_distiller/core/task_tracker.cc
@@ -6,6 +6,7 @@
 
 #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"
 #include "components/dom_distiller/core/proto/distilled_page.pb.h"
 
@@ -20,8 +21,11 @@ ViewerHandle::~ViewerHandle() {
   }
 }
 
-TaskTracker::TaskTracker(const ArticleEntry& entry, CancelCallback callback)
+TaskTracker::TaskTracker(const ArticleEntry& entry,
+                         CancelCallback callback,
+                         DistilledContentStore* content_store)
     : cancel_callback_(callback),
+      content_store_(content_store),
       entry_(entry),
       distilled_article_(),
       content_ready_(false),
@@ -40,7 +44,6 @@ void TaskTracker::StartDistiller(DistillerFactory* factory) {
   if (entry_.pages_size() == 0) {
     return;
   }
-
   GURL url(entry_.pages(0).url());
   DCHECK(url.is_valid());
 
@@ -53,9 +56,11 @@ void TaskTracker::StartDistiller(DistillerFactory* factory) {
 }
 
 void TaskTracker::StartBlobFetcher() {
-  // TODO(cjhopman): There needs to be some local storage for the distilled
-  // blob. When that happens, this should start some task to fetch the blob for
-  // |entry_| and asynchronously notify |this| when it is done.
+  if (content_store_) {
+    content_store_->LoadContent(entry_,
+                                base::Bind(&TaskTracker::OnBlobFetched,
+                                           weak_ptr_factory_.GetWeakPtr()));
+  }
 }
 
 void TaskTracker::AddSaveCallback(const SaveCallback& callback) {
@@ -146,11 +151,23 @@ void TaskTracker::NotifyViewer(ViewRequestDelegate* delegate) {
 
 void TaskTracker::OnDistillerFinished(
     scoped_ptr<DistilledArticleProto> distilled_article) {
-  OnDistilledArticleReady(distilled_article.Pass());
+  if (!content_ready_) {
+    OnDistilledArticleReady(distilled_article.Pass());
+  }
+}
+
+void TaskTracker::OnBlobFetched(
+    bool success,
+    scoped_ptr<DistilledArticleProto> distilled_article) {
+  if (!content_ready_ && success) {
+    OnDistilledArticleReady(distilled_article.Pass());
+  }
 }
 
 void TaskTracker::OnDistilledArticleReady(
     scoped_ptr<DistilledArticleProto> distilled_article) {
+  DCHECK(!content_ready_);
+  content_ready_ = true;
   distilled_article_ = distilled_article.Pass();
   bool distillation_successful = false;
   if (distilled_article_->pages_size() > 0) {