introduce DocumentParserClient to receive parser stopped notification

Source/core/dom/DocumentParser.cpp

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 #include "config.h"
 #include "core/dom/DocumentParser.h"
 
 #include "core/dom/Document.h"
+#include "core/dom/DocumentParserClient.h"
 #include "core/html/parser/TextResourceDecoder.h"
 #include "wtf/Assertions.h"
 
 namespace blink {
 
 DocumentParser::DocumentParser(Document* document)
     : m_state(ParsingState)
     , m_documentWasLoadedAsPartOfNavigation(false)
     , m_document(document)
 {
     ASSERT(document);
 }
 
 DocumentParser::~DocumentParser()
 {
 #if !ENABLE(OILPAN)
     // Document is expected to call detach() before releasing its ref.
     // This ASSERT is slightly awkward for parsers with a fragment case
     // as there is no Document to release the ref.
     ASSERT(!m_document);
 #endif
 }
 
 void DocumentParser::trace(Visitor* visitor)
 {
     visitor->trace(m_document);
+    // HELPME(oilpan): Below doesn't compile
+    // visitor->trace(m_clients);

[kouhei (in TOK), 2014/09/03 22:40:41]

This gives me an error, but I don't know how to resolve this:

../../third_party/WebKit/Source/platform/heap/Visitor.h:297:33: error: cannot
initialize a parameter of type 'typename DefaultAllocator::Visitor *' (aka
'WTF::DefaultAllocatorDummyVisitor *') with an rvalue of type 'blink::Visitor *'
        const_cast<T&>(t).trace(this);
                                ^~~~
../../third_party/WebKit/Source/core/dom/DocumentParser.cpp:57:14: note: in
instantiation of function template specialization
'blink::Visitor::trace<WTF::HashSet<WTF::RawPtr<blink::DocumentParserClient>,
WTF::PtrHash<WTF::RawPtr<blink::DocumentParserClient> >,
WTF::HashTraits<WTF::RawPtr<blink::DocumentParserClient> >,
WTF::DefaultAllocator> >' requested here
    visitor->trace(m_clients);
             ^
../../third_party/WebKit/Source/wtf/HashSet.h:111:49: note: passing argument to
parameter 'visitor' here
        void trace(typename Allocator::Visitor* visitor) {
m_impl.trace(visitor); }

[kouhei (in TOK), 2014/09/04 21:08:01]

Resolved. We needed a #if ENABLE(OILPAN) here, as the m_clients were
WillBeGCMixin.

 }
 
 void DocumentParser::setDecoder(PassOwnPtr<TextResourceDecoder>)
 {
     ASSERT_NOT_REACHED();
 }
 
 TextResourceDecoder* DocumentParser::decoder()
 {
     return 0;
 }
 
 void DocumentParser::prepareToStopParsing()
 {
     ASSERT(m_state == ParsingState);
     m_state = StoppingState;
 }
 
 void DocumentParser::stopParsing()
 {
     m_state = StoppedState;
+
+    // Clients may be removed while in the loop. Make a snapshot for iteration.
+    WillBeHeapVector<RawPtrWillBeMember<DocumentParserClient> > clientsSnapshot;
+    copyToVector(m_clients, clientsSnapshot);
+
+    for (WillBeHeapVector<RawPtrWillBeMember<DocumentParserClient> >::const_iterator it = clientsSnapshot.begin(), itEnd = clientsSnapshot.end(); it != itEnd; ++it) {
+        DocumentParserClient* client = *it;
+        if (!m_clients.contains(client))
+            continue;
+
+        client->notifyParserStopped();
+    }
 }
 
 void DocumentParser::detach()
 {
     m_state = DetachedState;
     m_document = nullptr;
 }
 
 void DocumentParser::suspendScheduledTasks()
 {
 }
 
 void DocumentParser::resumeScheduledTasks()
 {
 }
 
+void DocumentParser::addClient(DocumentParserClient* client)
+{
+    m_clients.add(client);
+}
+
+void DocumentParser::removeClient(DocumentParserClient* client)
+{
+    m_clients.remove(client);
+}
+
 };