Preload scan external css for @import

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

Index: third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.h
diff --git a/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.h b/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.h
index 2d23e7e7af4fed8187c7e53ec77108d883314c14..49b57dcd2d4dd3e08e96e2270773b8e1b642e2aa 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.h
+++ b/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.h
@@ -28,6 +28,7 @@
 
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/Resource.h"
+#include "core/html/parser/CSSPreloadScanner.h"
 #include "core/html/parser/PreloadRequest.h"
 #include "core/html/parser/ResourcePreloader.h"
 #include "core/loader/NetworkHintsInterface.h"
@@ -35,11 +36,12 @@
 
 namespace blink {
 
-class CORE_EXPORT HTMLResourcePreloader final : public GarbageCollected<HTMLResourcePreloader>, public ResourcePreloader {
+class CORE_EXPORT HTMLResourcePreloader final : public GarbageCollectedFinalized<HTMLResourcePreloader>, public ResourcePreloader {
     WTF_MAKE_NONCOPYABLE(HTMLResourcePreloader);
     friend class HTMLResourcePreloaderTest;
 public:
     static HTMLResourcePreloader* create(Document&);
+    int countPreloads();
     DECLARE_TRACE();
 
 protected:
@@ -49,6 +51,7 @@ private:
     explicit HTMLResourcePreloader(Document&);
 
     Member<Document> m_document;
+    HashSet<OwnPtr<CSSPreloaderResourceClient>> m_cssPreloaders;
 };
 
 } // namespace blink