Preload scan external CSS for @import

third_party/WebKit/Source/core/fetch/Resource.h

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller <mueller@kde.org>
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
@@ skipping 108 matching lines @@
 
     // This url can have a fragment, but it can match resources that differ by the fragment only.
     const KURL& url() const { return m_resourceRequest.url();}
     Type getType() const { return static_cast<Type>(m_type); }
     const ResourceLoaderOptions& options() const { return m_options; }
     ResourceLoaderOptions& mutableOptions() { return m_options; }
 
     void didChangePriority(ResourceLoadPriority, int intraPriorityValue);
     virtual ResourcePriority priorityFromObservers() { return ResourcePriority(); }
 
-    void addClient(ResourceClient*);
+    // |passive| indicates that the client should not affect whether a preload
+    // considers itself referenced.
+    void addClient(ResourceClient*, bool passive = false);

[hiroshige, 2016/06/17 12:15:17]

Defining and using enum instead of |bool| will be clearer.

Also, the name |passive| looks like more general than this flag actually does --
controlling whether to update PreloadReferenced status.
More specific enum value names like |MarkAsReferenced| / |DontMarkAsReferenced|
is better.

[Charlie Harrison, 2016/07/13 18:18:14]

Done.

     void removeClient(ResourceClient*);
     virtual bool hasClientsOrObservers() const { return !m_clients.isEmpty() || !m_clientsAwaitingCallback.isEmpty() || !m_finishedClients.isEmpty(); }
 
     enum PreloadResult {
         PreloadNotReferenced,
         PreloadReferenced,
         PreloadReferencedWhileLoading,
         PreloadReferencedWhileComplete
     };
     PreloadResult getPreloadResult() const { return static_cast<PreloadResult>(m_preloadResult); }
@@ skipping 107 matching lines @@
 
     virtual void destroyDecodedDataForFailedRevalidation() { }
 
     void setEncodedSize(size_t);
     void setDecodedSize(size_t);
     void didAccessDecodedData();
 
     void finishPendingClients();
 
     virtual void didAddClient(ResourceClient*);
-    void willAddClientOrObserver();
+    void willAddClientOrObserver(bool passive = false);

[hiroshige, 2016/06/17 12:15:17]

Please do not set default value for |passive| here, because
willAddClientOrObserver() is an internal method of Resource and making the
|passive| value always explicit will result in better code and easier bug
detection in the future.

[Charlie Harrison, 2016/07/13 18:18:14]

Done.

 
     // |this| object may be dead after didRemoveClientOrObserver().
     void didRemoveClientOrObserver();
     virtual void allClientsAndObserversRemoved();
 
     HashCountedSet<ResourceClient*> m_clients;
     HashCountedSet<ResourceClient*> m_clientsAwaitingCallback;
     HashCountedSet<ResourceClient*> m_finishedClients;
 
     bool hasClient(ResourceClient* client) { return m_clients.contains(client) || m_clientsAwaitingCallback.contains(client) || m_finishedClients.contains(client); }
@@ skipping 89 matching lines @@
 
     Resource::Type m_type;
 };
 
 #define DEFINE_RESOURCE_TYPE_CASTS(typeName) \
     DEFINE_TYPE_CASTS(typeName##Resource, Resource, resource, resource->getType() == Resource::typeName, resource.getType() == Resource::typeName);
 
 } // namespace blink
 
 #endif