Oilpan: have PendingScripts trace their script elements.

Source/core/html/parser/HTMLScriptRunner.h

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 #ifndef HTMLScriptRunner_h
 #define HTMLScriptRunner_h
 
 #include "core/dom/PendingScript.h"
+#include "core/fetch/ResourceClient.h"
+#include "platform/heap/Handle.h"
 #include "wtf/Deque.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/text/TextPosition.h"
 
 namespace WebCore {
 
 class Resource;
 class ScriptResource;
 class Document;
 class Element;
 class LocalFrame;
 class HTMLScriptRunnerHost;
 class ScriptSourceCode;
 
-class HTMLScriptRunner {
-    WTF_MAKE_NONCOPYABLE(HTMLScriptRunner); WTF_MAKE_FAST_ALLOCATED;
+class HTMLScriptRunner FINAL : public NoBaseWillBeGarbageCollectedFinalized<HTMLScriptRunner>, private ResourceClient {
+    WTF_MAKE_NONCOPYABLE(HTMLScriptRunner); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    static PassOwnPtr<HTMLScriptRunner> create(Document* document, HTMLScriptRunnerHost* host)
+    static PassOwnPtrWillBeRawPtr<HTMLScriptRunner> create(Document* document, HTMLScriptRunnerHost* host)
     {
-        return adoptPtr(new HTMLScriptRunner(document, host));
+        return adoptPtrWillBeNoop(new HTMLScriptRunner(document, host));
     }
     ~HTMLScriptRunner();
 
     void detach();
 
     // Processes the passed in script and any pending scripts if possible.
-    void execute(PassRefPtr<Element> scriptToProcess, const TextPosition& scriptStartPosition);
+    void execute(PassRefPtrWillBeRawPtr<Element> scriptToProcess, const TextPosition& scriptStartPosition);
 
     void executeScriptsWaitingForLoad(Resource*);
     bool hasScriptsWaitingForResources() const { return m_hasScriptsWaitingForResources; }
     void executeScriptsWaitingForResources();
     bool executeScriptsWaitingForParsing();
 
     bool hasParserBlockingScript() const;
     bool isExecutingScript() const { return !!m_scriptNestingLevel; }
 
+    // ResourceClient
+    virtual void notifyFinished(Resource*) OVERRIDE;
+
+    void trace(Visitor*);
+
 private:
     HTMLScriptRunner(Document*, HTMLScriptRunnerHost*);
 
     LocalFrame* frame() const;
 
     enum PendingScriptType {
         PendingScriptBlockingParser,
         PendingScriptDeferred
     };
 
     void executeParsingBlockingScript();
     void executePendingScriptAndDispatchEvent(PendingScript&, PendingScriptType);
     void executeParsingBlockingScripts();
 
     void requestParsingBlockingScript(Element*);
     void requestDeferredScript(Element*);
     bool requestPendingScript(PendingScript&, Element*) const;
 
     void runScript(Element*, const TextPosition& scriptStartPosition);
 
     // Helpers for dealing with HTMLScriptRunnerHost
     void watchForLoad(PendingScript&);
     void stopWatchingForLoad(PendingScript&);
     bool isPendingScriptReady(const PendingScript&);
     ScriptSourceCode sourceFromPendingScript(const PendingScript&, bool& errorOccurred) const;
 
-    Document* m_document;
+    RawPtrWillBeMember<Document> m_document;
     HTMLScriptRunnerHost* m_host;

[haraken, 2014/05/29 01:46:08]

This raw pointer looks OK, but it'd be better if we could make it a Member.

The only derived class of HTMLScriptRunnerHost is HTMLDocumentParser, and
HTMLDocumentParser is already on heap.

[sof, 2014/05/29 06:02:07]

Yes, it is safe.

     PendingScript m_parserBlockingScript;
     Deque<PendingScript> m_scriptsToExecuteAfterParsing; // http://www.whatwg.org/specs/web-apps/current-work/#list-of-scripts-that-will-execute-when-the-document-has-finished-parsing

[haraken, 2014/05/29 01:46:08]

Add a FIXME to change this to a HeapDeque.

[sof, 2014/05/29 06:02:07]

It's a non-heap version for a reason. i.e., we cannot finalize that sequence
with the help of this HTMLScriptRunner object if it lives on the heap. So, no
FIXME.

     unsigned m_scriptNestingLevel;
 
     // We only want stylesheet loads to trigger script execution if script
     // execution is currently stopped due to stylesheet loads, otherwise we'd
     // cause nested script execution when parsing <style> tags since </style>
     // tags can cause Document to call executeScriptsWaitingForResources.
     bool m_hasScriptsWaitingForResources;
 };
 
 }
 
 #endif