Verify the order of RawResourceClient callbacks in DocumentThreadableLoader

third_party/WebKit/Source/core/fetch/RawResource.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 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 89 matching lines @@
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!resource || isRawResource(*resource));
     return static_cast<RawResource*>(resource);
 }
 
 class CORE_EXPORT RawResourceClient : public GarbageCollectedMixin, public ResourceClient {
 public:
     static bool isExpectedType(ResourceClient* client) { return client->getResourceClientType() == RawResourceType; }
     ResourceClientType getResourceClientType() const final { return RawResourceType; }
 
+    // The order of the callbacks is as follows:
+    // [Case 1] A successful load:
+    // 0+  redirectReceived() and/or dataSent()
+    // 1   responseReceived()
+    // 0-1 setSerializedCachedMetadata()
+    // 0+  dataReceived() or dataDownloaded(), but never both
+    // 1   notifyFinished() with errorOccurred() = false
+    // [Case 2] When redirect is blocked:
+    // 0+  redirectReceived() and/or dataSent()
+    // 1   redirectBlocked()
+    // 1   notifyFinished() with errorOccurred() = true
+    // [Case 3] Other failures:
+    //     notifyFinished() with errorOccurred() = true is called at any time
+    //     (unless notifyFinished() is already called).
+    // In all cases:
+    //     No callbacks are made after notifyFinished() or
+    //     removeClient() is called.
     virtual void dataSent(Resource*, unsigned long long /* bytesSent */, unsigned long long /* totalBytesToBeSent */) { }
     virtual void responseReceived(Resource*, const ResourceResponse&, std::unique_ptr<WebDataConsumerHandle>) { }
     virtual void setSerializedCachedMetadata(Resource*, const char*, size_t) { }
     virtual void dataReceived(Resource*, const char* /* data */, size_t /* length */) { }
     virtual void redirectReceived(Resource*, ResourceRequest&, const ResourceResponse&) { }
     virtual void redirectBlocked() {}
     virtual void dataDownloaded(Resource*, int) { }
     virtual void didReceiveResourceTiming(Resource*, const ResourceTimingInfo&) { }
 
     DEFINE_INLINE_VIRTUAL_TRACE() {}
 };
 
+// Checks the sequence of callbacks of RawResourceClient.
+// This can be used only when a RawResourceClient is added as a client to
+// at most one RawResource.
+class CORE_EXPORT RawResourceClientStateChecker final {
+public:
+    RawResourceClientStateChecker();
+    ~RawResourceClientStateChecker();
+
+    // Call before addClient()/removeClient() is called.
+    void willAddClient();
+    void willRemoveClient();
+
+    // Call RawResourceClientStateChecker::f() at the beginning of
+    // RawResourceClient::f().
+    void redirectReceived();
+    void redirectBlocked();
+    void dataSent();
+    void responseReceived();
+    void setSerializedCachedMetadata();
+    void dataReceived();
+    void dataDownloaded();
+    void notifyFinished(Resource*);
+
+private:
+    enum State {
+        NotAddedAsClient,
+        Started,
+        RedirectBlocked,
+        ResponseReceived,
+        SetSerializedCachedMetadata,
+        DataReceived,
+        DataDownloaded,
+        NotifyFinished
+    };
+    State m_state;
+};
+
 } // namespace blink
 
 #endif // RawResource_h