DO NOT SUBMIT: Sketching out ScriptLoader::executeScriptAsync.

third_party/WebKit/Source/core/dom/ScriptLoader.h

 /*
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef ScriptLoader_h
 #define ScriptLoader_h
 
 #include "core/CoreExport.h"
 #include "core/dom/PendingScript.h"
 #include "core/dom/ScriptRunner.h"
+#include "core/fetch/AccessControlStatus.h"
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/ResourceClient.h"
 #include "core/loader/resource/ScriptResource.h"
+#include "wtf/Functional.h"
 #include "wtf/text/TextPosition.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
+class CompiledScript;
 class Element;
 class ScriptLoaderClient;
 class ScriptSourceCode;
 class LocalFrame;
 
 class CORE_EXPORT ScriptLoader : public GarbageCollectedFinalized<ScriptLoader>,
                                  public ScriptResourceClient {
   USING_GARBAGE_COLLECTED_MIXIN(ScriptLoader);
 
  public:
@@ skipping 18 matching lines @@
       const String& typeAttributeValue,
       const String& languageAttributeValue,
       LegacyTypeSupport supportLegacyTypes);
 
   bool prepareScript(
       const TextPosition& scriptStartPosition = TextPosition::minimumPosition(),
       LegacyTypeSupport = DisallowLegacyTypeInTypeAttribute);
 
   String scriptCharset() const { return m_characterEncoding; }
   String scriptContent() const;
+
   // Returns false if and only if execution was blocked.
   bool executeScript(const ScriptSourceCode&);
+
+  // Similar to executeScript, except that the actual execution of the script
+  // may be scheduled to run asynchronously. The provided callback will be
+  // invoked immediately after execution completes (or immediately, if there is
+  // nothing to do), with true iff the execution completed without error
+  // (including if there is nothing to do). Only policy errors (that should
+  // produce an error event) are reported this way; compile errors are still OK.
+  using ExecuteScriptAsyncCallback =
+      WTF::Function<void(bool completedWithoutError)>;
+  void executeScriptAsync(const ScriptSourceCode&,
+                          std::unique_ptr<ExecuteScriptAsyncCallback>);
+
   virtual void execute();
 
   // XML parser calls these
   void dispatchLoadEvent();
   void dispatchErrorEvent();
   bool isScriptTypeSupported(LegacyTypeSupport) const;
 
   bool haveFiredLoadEvent() const { return m_haveFiredLoad; }
   bool willBeParserExecuted() const { return m_willBeParserExecuted; }
   bool readyToBeParserExecuted() const { return m_readyToBeParserExecuted; }
@@ skipping 38 matching lines @@
                bool createdByParser,
                bool isEvaluated,
                bool createdDuringDocumentWrite);
 
  private:
   bool ignoresLoadRequest() const;
   bool isScriptForEventSupported() const;
   void logScriptMIMEType(LocalFrame*, ScriptResource*, const String&);
 
   bool fetchScript(const String& sourceUrl, FetchRequest::DeferOption);
-  bool doExecuteScript(const ScriptSourceCode&);
+
+  // Separate stages of executeScript/executeScriptAsync.
+
+  // Called asynchronously after script compilation, to actually execute the
+  // script, after executeScriptAsync is invoked.
+  void continueExecuteScriptAsync(CompiledScript*,
+                                  Document* elementDocumentWhenCompiled,
+                                  std::unique_ptr<ExecuteScriptAsyncCallback>);
+
+  // Determines whether the script should be proceed to execution.
+  // Includes Content Security Policy and MIME type checks.
+  // Must be called directly before execution, to ensure that current policy is
+  // applied.
+  enum class CheckScriptResult { NothingToDo, Proceed, Abort };
+  CheckScriptResult checkScript(const ScriptSourceCode&);
+
+  // Called before script compilation, to determine the extent to which cached
+  // data about the script is sharable.
+  AccessControlStatus computeAccessControlStatus(const ScriptSourceCode&);
+
+  // Invokes the functor with the ScriptController, in a context where it script
+  // can run. Applies (and unapplies) state such as document.currentScript.
+  // This should be used to wrap the actual execution of the script.
+  template <typename Functor>
+  void asCurrentScript(const Functor&);
+
+  // Records time that the parser has been blocked on script execution.
+  void recordParserBlockedOnScriptExecutionSince(double startTime);
+
+  // End stages of executeScript/executeScriptAsync.
 
   ScriptLoaderClient* client() const;
 
   // ResourceClient
   void notifyFinished(Resource*) override;
   String debugName() const override { return "ScriptLoader"; }
 
   Member<Element> m_element;
   Member<ScriptResource> m_resource;
   WTF::OrdinalNumber m_startLineNumber;
@@ skipping 28 matching lines @@
   DocumentWriteIntervention m_documentWriteIntervention;
 
   Member<PendingScript> m_pendingScript;
 };
 
 ScriptLoader* toScriptLoaderIfPossible(Element*);
 
 }  // namespace blink
 
 #endif  // ScriptLoader_h