Add <link rel=preload> onload support for scripts and styles

third_party/WebKit/Source/core/loader/LinkPreloadResourceClients.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 LinkPreloadResourceClients_h
+#define LinkPreloadResourceClients_h
+
+#include "core/fetch/FontResource.h"
+#include "core/fetch/ImageResourceClient.h"
+#include "core/fetch/ResourceOwner.h"
+#include "core/fetch/ScriptResource.h"
+#include "core/fetch/StyleSheetResourceClient.h"
+
+namespace blink {
+
+class LinkLoader;
+
+class LinkPreloadResourceClient : public NoBaseWillBeGarbageCollectedFinalized<LinkPreloadResourceClient> {
+public:
+    virtual ~LinkPreloadResourceClient() { }
+
+    void triggerEvents(Resource*);
+    virtual void callSetResource(Resource*) = 0;

[Nate Chapin, 2016/01/13 23:52:24]

Maybe take the Resource* as a parameter in the various create()/constructor
functions instead of needing this virutal?

[Yoav Weiss, 2016/01/14 10:10:02]

good call! :)

+
+protected:
+    LinkPreloadResourceClient(LinkLoader*);
+private:
+    WeakPtr<LinkLoader> m_loader;

[Nate Chapin, 2016/01/13 23:52:23]

LinkLoader owns LinkPreloadResourceClient. Wouldn't m_loader only get cleared
when LinkPreloadResourceClient gets deleted?

[Yoav Weiss, 2016/01/14 10:10:02]

true. Previousely left the weakPtr around since the alternative is a raw pointer
(otherwise we have a circular ref), but maybe a raw pointer is better. Changed.

+};
+
+class LinkPreloadScriptResourceClient: public ResourceOwner<Resource, ScriptResourceClient>, public LinkPreloadResourceClient {

[Nate Chapin, 2016/01/13 23:52:23]

Here and below: If I understand oilpan correctly, the oilpan-heap superclass
should be listed first, so LinkPreloadResourceClient should come before
ResourceOwner.

[Yoav Weiss, 2016/01/14 10:10:02]

ok

+public:
+    static PassOwnPtr<LinkPreloadScriptResourceClient> create(LinkLoader* loader)
+    {
+        return adoptPtr(new LinkPreloadScriptResourceClient(loader));
+    }
+
+    ~LinkPreloadScriptResourceClient() override { clearResource(); }
+
+    virtual String debugName() const { return "LinkPreloadScript"; }
+
+    void notifyFinished(Resource* resource) override
+    {
+        triggerEvents(resource);
+        clearResource();

[Nate Chapin, 2016/01/13 23:52:24]

Why does notifyFinished() call clearResource() in
LinkPreloadScriptResourceClient, but not the other LinkPreloadResourceClients?

[Yoav Weiss, 2016/01/14 10:10:02]

leftover. Apologies.

+    }
+
+    void callSetResource(Resource* resource)
+    {
+        setResource(resource);
+    }
+
+private:
+    LinkPreloadScriptResourceClient(LinkLoader* loader)
+        : LinkPreloadResourceClient(loader)
+    {
+    }
+};
+
+class LinkPreloadStyleResourceClient: public ResourceOwner<Resource, StyleSheetResourceClient>, public LinkPreloadResourceClient {
+public:
+    static PassOwnPtr<LinkPreloadStyleResourceClient> create(LinkLoader* loader)
+    {
+        return adoptPtr(new LinkPreloadStyleResourceClient(loader));
+    }
+
+    virtual String debugName() const { return "LinkPreloadStyle"; }
+
+    void notifyFinished(Resource* resource) override
+    {
+        triggerEvents(resource);
+    }
+
+    void callSetResource(Resource* resource)
+    {
+        setResource(resource);
+    }
+
+private:
+    LinkPreloadStyleResourceClient(LinkLoader* loader)
+        : LinkPreloadResourceClient(loader)
+    {
+    }
+};
+
+class LinkPreloadImageResourceClient: public ResourceOwner<Resource, ImageResourceClient>, public LinkPreloadResourceClient {
+public:
+    static PassOwnPtr<LinkPreloadImageResourceClient> create(LinkLoader* loader)
+    {
+        return adoptPtr(new LinkPreloadImageResourceClient(loader));
+    }
+
+    virtual String debugName() const { return "LinkPreloadImage"; }
+
+    void notifyFinished(Resource* resource) override
+    {
+        triggerEvents(resource);
+    }
+
+    void callSetResource(Resource* resource)
+    {
+        setResource(resource);
+    }
+
+private:
+    LinkPreloadImageResourceClient(LinkLoader* loader)
+        : LinkPreloadResourceClient(loader)
+    {
+    }
+};
+
+}
+
+#endif // LinkPreloadResourceClients_h