Oilpan: enable appcache + move DocumentLoader to the heap.

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index 81dccfc934bbef72ffa70c5ee442d43c4bb35a20..25aba4dd04932f421d5aa008508267dd2609e3be 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -179,6 +179,9 @@ DEFINE_TRACE(FrameLoader)
 {
     visitor->trace(m_frame);
     visitor->trace(m_progressTracker);
+    visitor->trace(m_documentLoader);
+    visitor->trace(m_provisionalDocumentLoader);
+    visitor->trace(m_policyDocumentLoader);
     visitor->trace(m_currentItem);
     visitor->trace(m_provisionalItem);
     visitor->trace(m_deferredHistoryLoad);
@@ -315,7 +318,7 @@ void FrameLoader::replaceDocumentWhileExecutingJavaScriptURL(const String& sourc
 
     // DocumentLoader::replaceDocumentWhileExecutingJavaScriptURL can cause the DocumentLoader to get deref'ed and possible destroyed,
     // so protect it with a RefPtr.
-    RefPtr<DocumentLoader> documentLoader(m_frame->document()->loader());
+    RefPtrWillBeRawPtr<DocumentLoader> documentLoader(m_frame->document()->loader());
 
     UseCounter::count(*m_frame->document(), UseCounter::ReplaceDocumentViaJavaScriptURL);
 
@@ -1009,7 +1012,7 @@ void FrameLoader::notifyIfInitialDocumentAccessed()
 bool FrameLoader::prepareForCommit()
 {
     PluginScriptForbiddenScope forbidPluginDestructorScripting;
-    RefPtr<DocumentLoader> pdl = m_provisionalDocumentLoader;
+    RefPtrWillBeRawPtr<DocumentLoader> pdl = m_provisionalDocumentLoader;
 
     if (m_documentLoader) {
         client()->dispatchWillClose();