Fix crash in CSSStyleSheetResource::appendData

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

Index: third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp b/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp
index 88bf5409336fef8be9b651a9d47d7c5d63322a54..b9a7c933569c67c80594f18426eebd87e326e0b8 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp
+++ b/third_party/WebKit/Source/core/html/parser/HTMLResourcePreloader.cpp
@@ -47,6 +47,7 @@ HTMLResourcePreloader* HTMLResourcePreloader::create(Document& document)
 DEFINE_TRACE(HTMLResourcePreloader)
 {
     visitor->trace(m_document);
+    visitor->trace(m_cssPreloaders);
 }
 
 int HTMLResourcePreloader::countPreloads()
@@ -85,9 +86,7 @@ void HTMLResourcePreloader::preload(PassOwnPtr<PreloadRequest> preload, const Ne
     request.setForPreload(true);
     Resource* resource = m_document->loader()->startPreload(preload->resourceType(), request);
     if (resource && preload->resourceType() == Resource::CSSStyleSheet && RuntimeEnabledFeatures::cssPreloadImportEnabled()) {
-        OwnPtr<CSSPreloaderResourceClient> client = adoptPtr(new CSSPreloaderResourceClient(resource, this));
-        resource->addClient(client.get());
-        m_cssPreloaders.add(client.release());
+        m_cssPreloaders.append(new CSSPreloaderResourceClient(resource, this));
     }
 }