Fetch notification action icons and pass them through in resources.

content/child/notifications/pending_notification.h

+// Copyright 2016 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.
+
+#ifndef CONTENT_CHILD_NOTIFICATIONS_PENDING_NOTIFICATION_H_
+#define CONTENT_CHILD_NOTIFICATIONS_PENDING_NOTIFICATION_H_
+
+#include <set>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "content/child/notifications/notification_image_loader.h"
+#include "third_party/WebKit/public/platform/WebURL.h"
+#include "third_party/WebKit/public/platform/modules/notifications/WebNotificationData.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace content {
+
+struct NotificationResources;
+
+// Stores the information associated with a pending notification, and fetches
+// resources for it on the main thread.
+class PendingNotification {
+ public:
+  PendingNotification(
+      scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner,
+      const blink::WebNotificationData& notification_data,

[Peter Beverloo, 2016/02/05 15:43:21]

The only reason that PendingNotification stores the |notification_data| is to
access it in FetchResources(), which is called on the same thread.

The WebNotificationData object can be arbitrarily large (developer-provided
data), we can avoid this copy by taking a const& argument in FetchResources()
instead and only using what we need there.

[Michael van Ouwerkerk, 2016/02/08 14:38:52]

Ugh. The constructor does a bit more than that, and I like to have a sane
internal state after constructing. But, I would like to avoid this copy, so
Done.

+      const base::Closure& fetches_finished_callback);
+  ~PendingNotification();
+
+  // Fetches all resources asynchronously on the main thread.
+  void FetchResources();
+
+  // Returns a new NotificationResources populated with the resources that have
+  // been fetched.
+  NotificationResources GetResources();
+
+ private:
+  // Fetches an image using |image_web_url| asynchronously on the main thread.
+  // The |image_callback| will be called on the worker thread.
+  void FetchImageResource(const blink::WebURL& image_web_url,
+                          const ImageLoadCompletedCallback& image_callback);
+
+  // To be called on the worker thread when the notification icon has been
+  // fetched.
+  void DidFetchNotificationIcon(const SkBitmap& notification_icon);
+
+  // To be called on the worker thread when an action icon has been fetched.
+  void DidFetchActionIcon(size_t action_index, const SkBitmap& action_icon);
+
+  scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_;
+
+  blink::WebNotificationData notification_data_;
+
+  SkBitmap notification_icon_;
+
+  std::vector<SkBitmap> action_icons_;
+
+  base::Closure fetches_finished_barrier_closure_;
+
+  std::set<scoped_refptr<NotificationImageLoader>> image_loaders_;

[Peter Beverloo, 2016/02/05 15:43:21]

nit: May as well use a std::vector<> for this, since we don't use set semantics.

[Michael van Ouwerkerk, 2016/02/08 14:38:52]

Done.

+
+  base::WeakPtrFactory<PendingNotification> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PendingNotification);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_CHILD_NOTIFICATIONS_PENDING_NOTIFICATION_H_