Preload scan external css for @import

third_party/WebKit/Source/core/html/parser/CSSPreloadScanner.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef CSSPreloadScanner_h
 #define CSSPreloadScanner_h
 
-#include "core/html/parser/HTMLResourcePreloader.h"
+#include "core/fetch/StyleSheetResourceClient.h"
 #include "core/html/parser/HTMLToken.h"
+#include "core/html/parser/PreloadRequest.h"
 #include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 class SegmentedString;
+class HTMLResourcePreloader;
 
 class CSSPreloadScanner {
     DISALLOW_NEW();
     WTF_MAKE_NONCOPYABLE(CSSPreloadScanner);
 public:
     CSSPreloadScanner();
     ~CSSPreloadScanner();
 
     void reset();
 
@@ skipping 26 matching lines @@
     StringBuilder m_rule;
     StringBuilder m_ruleValue;
 
     ReferrerPolicy m_referrerPolicy = ReferrerPolicyDefault;
 
     // Below members only non-null during scan()
     PreloadRequestStream* m_requests = nullptr;
     const KURL* m_predictedBaseElementURL = nullptr;
 };
 
+// Each CSSPreloaderResourceClient keeps track of a single CSS resource, and
+// drives a CSSPreloadScanner as raw data arrives for it. This lets us preload
+// @import tags before parsing.
+class CSSPreloaderResourceClient : public StyleSheetResourceClient {
+public:
+    CSSPreloaderResourceClient(Resource*, HTMLResourcePreloader*);
+    void notifyFinished(Resource*) override;
+    void didAppendFirstData(const CSSStyleSheetResource*) override;
+    String debugName() const override { return "CSSPreloaderResourceClient"; }
+
+private:
+    Persistent<Resource> m_resource;
+    WeakPersistent<HTMLResourcePreloader> m_preloader;
+};
+
 } // namespace blink
 
 #endif