Check if stylesheet resource was cached before marking it as such.

third_party/WebKit/Source/core/fetch/CSSStyleSheetResource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
 
     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
@@ skipping 10 matching lines @@
     Boston, MA 02110-1301, USA.
 
     This class provides all functionality needed for loading images, style sheets and html
     pages from the web. It has a memory cache for these objects.
 */
 
 #include "core/fetch/CSSStyleSheetResource.h"
 
 #include "core/css/StyleSheetContents.h"
 #include "core/fetch/FetchRequest.h"
+#include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceClientWalker.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/fetch/StyleSheetResourceClient.h"
 #include "platform/SharedBuffer.h"
 #include "wtf/CurrentTime.h"
 
 namespace blink {
 
 PassRefPtrWillBeRawPtr<CSSStyleSheetResource> CSSStyleSheetResource::fetch(FetchRequest& request, ResourceFetcher* fetcher)
 {
@@ skipping 12 matching lines @@
 {
     DEFINE_STATIC_LOCAL(const AtomicString, acceptCSS, ("text/css,*/*;q=0.1", AtomicString::ConstructFromLiteral));
 
     // Prefer text/css but accept any type (dell.com serves a stylesheet
     // as text/html; see <http://bugs.webkit.org/show_bug.cgi?id=11451>).
     setAccept(acceptCSS);
 }
 
 CSSStyleSheetResource::~CSSStyleSheetResource()
 {
-    // Make sure dispose() was cllaed before destruction.
-    ASSERT(!m_parsedStyleSheetCache);
 }
 
 void CSSStyleSheetResource::removedFromMemoryCache()
 {
     if (m_parsedStyleSheetCache)
         m_parsedStyleSheetCache->removedFromMemoryCache();
     m_parsedStyleSheetCache.clear();
     Resource::removedFromMemoryCache();
 }
 
@@ skipping 98 matching lines @@
     return m_parsedStyleSheetCache;
 }
 
 void CSSStyleSheetResource::saveParsedStyleSheet(PassRefPtrWillBeRawPtr<StyleSheetContents> sheet)
 {
     ASSERT(sheet && sheet->isCacheable());
 
     if (m_parsedStyleSheetCache)
         m_parsedStyleSheetCache->removedFromMemoryCache();
     m_parsedStyleSheetCache = sheet;
-    m_parsedStyleSheetCache->addedToMemoryCache();
 
     setDecodedSize(m_parsedStyleSheetCache->estimatedSizeInBytes());
+
+    // Check if this stylesheet resource didn't conflict with
+    // another resource and has indeed been added to the cache.
+    if (memoryCache()->contains(this))
+        m_parsedStyleSheetCache->addedToMemoryCache();
 }
 
 } // namespace blink