Move notification resource loading from content/child to blink

third_party/WebKit/Source/modules/notifications/NotificationResourcesLoader.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 NotificationResourcesLoader_h
+#define NotificationResourcesLoader_h
+
+#include "core/dom/ContextLifecycleObserver.h"
+#include "modules/ModulesExport.h"
+#include "modules/notifications/NotificationImageLoader.h"
+#include "platform/heap/GarbageCollected.h"
+#include "platform/heap/Handle.h"
+#include "platform/heap/HeapAllocator.h"
+#include "platform/heap/ThreadState.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "wtf/Functional.h"
+#include "wtf/OwnPtr.h"
+#include "wtf/PassOwnPtr.h"
+#include "wtf/Vector.h"
+#include <memory>
+
+namespace blink {
+
+class ExecutionContext;
+struct WebNotificationData;
+struct WebNotificationResources;
+
+class MODULES_EXPORT NotificationResourcesLoader final
+    : public GarbageCollectedFinalized<NotificationResourcesLoader>
+    , public ContextLifecycleObserver {
+    USING_GARBAGE_COLLECTED_MIXIN(NotificationResourcesLoader);
+    USING_PRE_FINALIZER(NotificationResourcesLoader, stop);
+public:
+    using CompletionCallback = Function<void(NotificationResourcesLoader*)>;

[Peter Beverloo, 2016/04/13 18:32:28]

Docs? Would be good to document that the instance is passed because we store a
set of 'em in ServiceWorkerRegistrationNotifications. (It looks a bit odd when
looking at Notification.cpp, which intuitively is where most people start.)

[Michael van Ouwerkerk, 2016/04/14 13:42:12]

Done.

+    NotificationResourcesLoader(ExecutionContext*,
+        PassOwnPtr<CompletionCallback>);

[Peter Beverloo, 2016/04/13 18:32:28]

micro nit: nowrap

[Michael van Ouwerkerk, 2016/04/14 13:42:12]

Done.

+    ~NotificationResourcesLoader();
+
+    // Starts fetching the resources specified in the given WebNotificationData.
+    // If all the urls for the resources are empty or invalid,
+    // |m_completionCallback| will be run synchronously, otherwise it will be
+    // run asynchronously when all fetches have finished. Should not be called
+    // more than once.

[Peter Beverloo, 2016/04/13 18:32:28]

Is there any way we can DCHECK for this contract? Even if not completely
thorough, something like the following could be a start:

    DCHECK(!m_pendingRequestCount && m_actionIcons.empty());

[Michael van Ouwerkerk, 2016/04/14 13:42:12]

I've added m_started for this.

+    void start(const WebNotificationData&);
+
+    // Returns a new WebNotificationResources populated with the resources that
+    // have been fetched.
+    std::unique_ptr<WebNotificationResources> getResources() const;
+
+    // ContextLifecycleObserver interface.
+    void contextDestroyed() override;
+
+    DECLARE_VIRTUAL_TRACE();
+
+private:
+    void loadImage(const KURL&,
+        PassOwnPtr<NotificationImageLoader::ImageCallback>);

[Peter Beverloo, 2016/04/13 18:32:28]

micro nit: nowrap

(This is invalid per Chromium style too.)

[Michael van Ouwerkerk, 2016/04/14 13:42:12]

Done.

+    void didLoadIcon(const SkBitmap& image);
+    void didLoadBadge(const SkBitmap& image);
+    void didLoadActionIcon(size_t actionIndex, const SkBitmap& image);
+
+    // Decrements |m_pendingRequestCount| and runs |m_completionCallback| if
+    // there are no more pending requests.
+    void didFinishRequest();
+
+    // Stops every loader in |m_imageLoaders|.

[Peter Beverloo, 2016/04/13 18:32:28]

nit: Also document that this is the pre-finalizer. (The macro on line 32 is easy
to miss.)

[Michael van Ouwerkerk, 2016/04/14 13:42:12]

Done.

+    void stop();
+
+    OwnPtr<CompletionCallback> m_completionCallback;
+    int m_pendingRequestCount;
+    HeapVector<Member<NotificationImageLoader>> m_imageLoaders;
+    SkBitmap m_icon;
+    SkBitmap m_badge;
+    Vector<SkBitmap> m_actionIcons;
+};
+
+} // namespace blink
+
+#endif // NotificationResourcesLoader_h