Oilpan: move MHTML objects to the heap.

Source/platform/mhtml/MHTMLArchive.cpp

Index: Source/platform/mhtml/MHTMLArchive.cpp
diff --git a/Source/platform/mhtml/MHTMLArchive.cpp b/Source/platform/mhtml/MHTMLArchive.cpp
index fe1ecc39b2080e043e174b9b53cb1c837f2daf7d..8cc1f9cbe70f230ab06584d56028e4c833172a4a 100644
--- a/Source/platform/mhtml/MHTMLArchive.cpp
+++ b/Source/platform/mhtml/MHTMLArchive.cpp
@@ -35,6 +35,7 @@
 #include "platform/MIMETypeRegistry.h"
 #include "platform/SerializedResource.h"
 #include "platform/SharedBuffer.h"
+#include "platform/mhtml/ArchiveResource.h"
 #include "platform/mhtml/MHTMLParser.h"
 #include "platform/text/QuotedPrintable.h"
 #include "platform/weborigin/SchemeRegistry.h"
@@ -86,29 +87,31 @@ MHTMLArchive::MHTMLArchive()
 
 MHTMLArchive::~MHTMLArchive()
 {
+#if !ENABLE(OILPAN)
     // Because all frames know about each other we need to perform a deep clearing of the archives graph.
     clearAllSubframeArchives();
+#endif
 }
 
-PassRefPtr<MHTMLArchive> MHTMLArchive::create()
+PassRefPtrWillBeRawPtr<MHTMLArchive> MHTMLArchive::create()
 {
-    return adoptRef(new MHTMLArchive);
+    return adoptRefWillBeNoop(new MHTMLArchive);
 }
 
-PassRefPtr<MHTMLArchive> MHTMLArchive::create(const KURL& url, SharedBuffer* data)
+PassRefPtrWillBeRawPtr<MHTMLArchive> MHTMLArchive::create(const KURL& url, SharedBuffer* data)
 {
     // For security reasons we only load MHTML pages from local URLs.
     if (!SchemeRegistry::shouldTreatURLSchemeAsLocal(url.protocol()))
         return nullptr;
 
     MHTMLParser parser(data);
-    RefPtr<MHTMLArchive> mainArchive = parser.parseArchive();
+    RefPtrWillBeRawPtr<MHTMLArchive> mainArchive = parser.parseArchive();
     if (!mainArchive)
         return nullptr; // Invalid MHTML file.
 
     // Since MHTML is a flat format, we need to make all frames aware of all resources.
     for (size_t i = 0; i < parser.frameCount(); ++i) {
-        RefPtr<MHTMLArchive> archive = parser.frameAt(i);
+        RefPtrWillBeRawPtr<MHTMLArchive> archive = parser.frameAt(i);
         for (size_t j = 1; j < parser.frameCount(); ++j) {
             if (i != j)
                 archive->addSubframeArchive(parser.frameAt(j));
@@ -216,13 +219,13 @@ PassRefPtr<SharedBuffer> MHTMLArchive::generateMHTMLData(const Vector<Serialized
 
 void MHTMLArchive::clearAllSubframeArchives()

[haraken, 2014/07/08 08:50:08]

I'm curious why we need to call clearAllSubframeArchives() even in non-oilpan
builds. What clearAllSubframeArchives() does is just to call
m_subframeArchives.clear() for all subframes. I don't think this is needed,
because m_subframeArchives.clear() will be called in the destructor of the
subframes.

In other words, if we really need to call clearAllSubframeArchives() in
non-oilpan builds for some reason (e.g., we want to forcibly clear archives of
the subframes even though there are other retainers of the subframes somewhere),
won't it mean that we want to call clearAllSubframeArchives() in oilpan builds
as well?

[haraken, 2014/07/08 08:50:08]

Can we add #if !ENABLE(OILPAN) to this method?

[sof, 2014/07/08 09:10:00]

I think you're right, I didn't see the point of this operation either, but
didn't want to upset the apple cart. The operation being to DFS visit all
archives and then deref() them all in the end.

The deref() storm that will happen when the vector is destructed should take
care of this already. The comment in the dtor makes me uncertain if the thinking
is that there might be loops here needing this..in which case we'll never get
here due to the use of RefPtrs.

 {
-    Vector<RefPtr<MHTMLArchive> > clearedArchives;
+    SubFrameArchives clearedArchives;
     clearAllSubframeArchivesImpl(&clearedArchives);
 }
 
-void MHTMLArchive::clearAllSubframeArchivesImpl(Vector<RefPtr<MHTMLArchive> >* clearedArchives)
+void MHTMLArchive::clearAllSubframeArchivesImpl(SubFrameArchives* clearedArchives)

[haraken, 2014/07/08 08:50:07]

Ditto.

 {
-    for (Vector<RefPtr<MHTMLArchive> >::iterator it = m_subframeArchives.begin(); it != m_subframeArchives.end(); ++it) {
+    for (SubFrameArchives::iterator it = m_subframeArchives.begin(); it != m_subframeArchives.end(); ++it) {
         if (!clearedArchives->contains(*it)) {
             clearedArchives->append(*it);
             (*it)->clearAllSubframeArchivesImpl(clearedArchives);
@@ -231,4 +234,11 @@ void MHTMLArchive::clearAllSubframeArchivesImpl(Vector<RefPtr<MHTMLArchive> >* c
     m_subframeArchives.clear();
 }
 
+void MHTMLArchive::trace(Visitor* visitor)
+{
+    visitor->trace(m_mainResource);
+    visitor->trace(m_subresources);
+    visitor->trace(m_subframeArchives);
+}
+
 }