Remove ResourceFetcher's access to a real FetchContext at frame detach time

Source/core/loader/DocumentLoader.cpp

Index: Source/core/loader/DocumentLoader.cpp
diff --git a/Source/core/loader/DocumentLoader.cpp b/Source/core/loader/DocumentLoader.cpp
index ee5bdd90d001dbed3d1e44d18044f7af617312e7..7b10a32dfcb4de150e0751470418fe78b8959baf 100644
--- a/Source/core/loader/DocumentLoader.cpp
+++ b/Source/core/loader/DocumentLoader.cpp
@@ -107,7 +107,6 @@ ResourceLoader* DocumentLoader::mainResourceLoader() const
 DocumentLoader::~DocumentLoader()
 {
     ASSERT(!m_frame || !isLoading());
-    static_cast<FrameFetchContext&>(m_fetcher->context()).clearDocumentLoader();
     clearMainResourceHandle();
     m_applicationCacheHost->dispose();
 }
@@ -562,6 +561,7 @@ void DocumentLoader::detachFromFrame()
     // frame have any loads active, so go ahead and kill all the loads.
     stopLoading();
 
+    m_fetcher->clearContext();
     m_applicationCacheHost->setApplicationCache(0);
     InspectorInstrumentation::loaderDetachedFromFrame(m_frame, this);
     m_frame = 0;