Defer late and async scripts

Source/core/html/parser/HTMLPreloadScanner.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 93 matching lines @@
 class TokenPreloadScanner::StartTagScanner {
 public:
     StartTagScanner(const StringImpl* tagImpl, PassRefPtr<MediaValues> mediaValues)
         : m_tagImpl(tagImpl)
         , m_linkIsStyleSheet(false)
         , m_matchedMediaAttribute(true)
         , m_inputIsImage(false)
         , m_sourceSize(0)
         , m_sourceSizeSet(false)
         , m_isCORSEnabled(false)
+        , m_execAsync(false)
         , m_allowCredentials(DoNotAllowStoredCredentials)
         , m_mediaValues(mediaValues)
     {
         if (match(m_tagImpl, imgTag)
             || match(m_tagImpl, sourceTag)) {
             if (RuntimeEnabledFeatures::pictureSizesEnabled())
                 m_sourceSize = SizesAttributeParser(m_mediaValues, String()).length();
             return;
         }
         if ( !match(m_tagImpl, inputTag)
@@ skipping 39 matching lines @@
     {
         if (!shouldPreload() || !m_matchedMediaAttribute)
             return nullptr;
 
         TRACE_EVENT_INSTANT1("net", "PreloadRequest", "url", m_urlToLoad.ascii());
         TextPosition position = TextPosition(source.currentLine(), source.currentColumn());
         OwnPtr<PreloadRequest> request = PreloadRequest::create(initiatorFor(m_tagImpl), position, m_urlToLoad, predictedBaseURL, resourceType());
         if (isCORSEnabled())
             request->setCrossOriginEnabled(allowStoredCredentials());
         request->setCharset(charset());
+        request->setExecAsync(m_execAsync);
         return request.release();
     }
 
 private:
     template<typename NameType>
     void processScriptAttribute(const NameType& attributeName, const String& attributeValue)
     {
         // FIXME - Don't set crossorigin multiple times.
         if (match(attributeName, srcAttr))
             setUrlToLoad(attributeValue, DisallowURLReplacement);
         else if (match(attributeName, crossoriginAttr))
             setCrossOriginAllowed(attributeValue);
+        else if (match(attributeName, asyncAttr))
+            setExecAsync(true);
+        else if (match(attributeName, deferAttr))
+            setExecAsync(true);
     }
 
     template<typename NameType>
     void processImgAttribute(const NameType& attributeName, const String& attributeValue)
     {
         if (match(attributeName, srcAttr) && m_imgSrcUrl.isNull()) {
             m_imgSrcUrl = attributeValue;
             setUrlToLoad(bestFitSourceForImageAttributes(m_mediaValues->devicePixelRatio(), m_sourceSize, attributeValue, m_srcsetImageCandidate), AllowURLReplacement);
         } else if (match(attributeName, crossoriginAttr)) {
             setCrossOriginAllowed(attributeValue);
@@ skipping 135 matching lines @@
 
     void setCrossOriginAllowed(const String& corsSetting)
     {
         m_isCORSEnabled = true;
         if (!corsSetting.isNull() && equalIgnoringCase(stripLeadingAndTrailingHTMLSpaces(corsSetting), "use-credentials"))
             m_allowCredentials = AllowStoredCredentials;
         else
             m_allowCredentials = DoNotAllowStoredCredentials;
     }
 
+    void setExecAsync(const bool execAsync)
+    {
+        m_execAsync = execAsync;
+    }
+
+    bool execAsync() const
+    {
+        return m_execAsync;
+    }
+
     const StringImpl* m_tagImpl;
     String m_urlToLoad;
     ImageCandidate m_srcsetImageCandidate;
     String m_charset;
     bool m_linkIsStyleSheet;
     bool m_matchedMediaAttribute;
     bool m_inputIsImage;
     String m_imgSrcUrl;
     String m_srcsetAttributeValue;
     unsigned m_sourceSize;
     bool m_sourceSizeSet;
     bool m_isCORSEnabled;
+    bool m_execAsync;
     StoredCredentials m_allowCredentials;
     RefPtr<MediaValues> m_mediaValues;
 };
 
 TokenPreloadScanner::TokenPreloadScanner(const KURL& documentURL, PassRefPtr<MediaValues> mediaValues)
     : m_documentURL(documentURL)
     , m_inStyle(false)
     , m_inPicture(false)
+    , m_isBeforeBody(true)
     , m_templateCount(0)
     , m_mediaValues(mediaValues)
 {
 }
 
 TokenPreloadScanner::~TokenPreloadScanner()
 {
 }
 
 TokenPreloadScannerCheckpoint TokenPreloadScanner::createCheckpoint()
 {
     TokenPreloadScannerCheckpoint checkpoint = m_checkpoints.size();
-    m_checkpoints.append(Checkpoint(m_predictedBaseElementURL, m_inStyle, m_templateCount));
+    m_checkpoints.append(Checkpoint(m_predictedBaseElementURL, m_inStyle, m_isBeforeBody, m_templateCount));
     return checkpoint;
 }
 
 void TokenPreloadScanner::rewindTo(TokenPreloadScannerCheckpoint checkpointIndex)
 {
     ASSERT(checkpointIndex < m_checkpoints.size()); // If this ASSERT fires, checkpointIndex is invalid.
     const Checkpoint& checkpoint = m_checkpoints[checkpointIndex];
     m_predictedBaseElementURL = checkpoint.predictedBaseElementURL;
     m_inStyle = checkpoint.inStyle;
+    m_isBeforeBody = checkpoint.isBeforeBody;
     m_templateCount = checkpoint.templateCount;
     m_cssScanner.reset();
+    m_cssScanner.setIsBeforeBody(m_isBeforeBody);
     m_checkpoints.clear();
 }
 
 void TokenPreloadScanner::scan(const HTMLToken& token, const SegmentedString& source, PreloadRequestStream& requests)
 {
     scanCommon(token, source, requests);
 }
 
 void TokenPreloadScanner::scan(const CompactHTMLToken& token, const SegmentedString& source, PreloadRequestStream& requests)
 {
@@ skipping 32 matching lines @@
             return;
         const StringImpl* tagImpl = tagImplFor(token.data());
         if (match(tagImpl, templateTag)) {
             ++m_templateCount;
             return;
         }
         if (match(tagImpl, styleTag)) {
             m_inStyle = true;
             return;
         }
+        if (m_isBeforeBody && match(tagImpl, bodyTag)) {
+            m_isBeforeBody = false;
+            m_cssScanner.setIsBeforeBody(m_isBeforeBody);
+        }
         if (match(tagImpl, baseTag)) {
             // The first <base> element is the one that wins.
             if (!m_predictedBaseElementURL.isEmpty())
                 return;
             updatePredictedBaseURL(token);
             return;
         }
         if (RuntimeEnabledFeatures::pictureEnabled() && (match(tagImpl, pictureTag))) {
             m_inPicture = true;
             m_pictureSourceURL = String();
             return;
         }
 
         StartTagScanner scanner(tagImpl, m_mediaValues);
         scanner.processAttributes(token.attributes());
         if (m_inPicture)
             scanner.handlePictureSourceURL(m_pictureSourceURL);
         OwnPtr<PreloadRequest> request = scanner.createPreloadRequest(m_predictedBaseElementURL, source);
-        if (request)
+        if (request) {
+            request->setIsBeforeBody(m_isBeforeBody);
             requests.append(request.release());
+        }
         return;
     }
     default: {
         return;
     }
     }
 }
 
 template<typename Token>
 void TokenPreloadScanner::updatePredictedBaseURL(const Token& token)
@@ skipping 34 matching lines @@
         if (m_token.type() == HTMLToken::StartTag)
             m_tokenizer->updateStateFor(attemptStaticStringCreation(m_token.name(), Likely8Bit));
         m_scanner.scan(m_token, m_source, requests);
         m_token.clear();
     }
 
     preloader->takeAndPreload(requests);
 }
 
 }