Make XHR use the background HTML parser

Source/core/xml/XMLHttpRequest.cpp

Index: Source/core/xml/XMLHttpRequest.cpp
diff --git a/Source/core/xml/XMLHttpRequest.cpp b/Source/core/xml/XMLHttpRequest.cpp
index 5d1979176606a13ed6a09d9ed92e6b2ea6dbbf97..4698049962df7fcdf463adcd55703994309f4819 100644
--- a/Source/core/xml/XMLHttpRequest.cpp
+++ b/Source/core/xml/XMLHttpRequest.cpp
@@ -131,6 +131,13 @@ private:
     RawPtrWillBeMember<XMLHttpRequest> m_owner;
 };
 
+HashMap<Document*, XMLHttpRequest*>& xhrPendingDocumentParseMap()
+{
+    typedef HashMap<Document*, XMLHttpRequest*> XHRPendingDocumentParseMap;
+    DEFINE_STATIC_LOCAL(XHRPendingDocumentParseMap, map, ());
+    return map;
+}
+
 } // namespace
 
 PassRefPtrWillBeRawPtr<XMLHttpRequest> XMLHttpRequest::create(ExecutionContext* context, PassRefPtr<SecurityOrigin> securityOrigin)
@@ -144,6 +151,7 @@ PassRefPtrWillBeRawPtr<XMLHttpRequest> XMLHttpRequest::create(ExecutionContext*
 XMLHttpRequest::XMLHttpRequest(ExecutionContext* context, PassRefPtr<SecurityOrigin> securityOrigin)
     : ActiveDOMObject(context)
     , m_timeoutMilliseconds(0)
+    , m_loaderIdentifier(0)
     , m_state(UNSENT)
     , m_downloadedBlobLength(0)
     , m_receivedLength(0)
@@ -935,6 +943,14 @@ bool XMLHttpRequest::internalAbort()
 
     InspectorInstrumentation::didFailXHRLoading(executionContext(), this, this);
 
+    HashMap<Document*, XMLHttpRequest*>& map = xhrPendingDocumentParseMap();
+    for (HashMap<Document*, XMLHttpRequest*>::iterator it = map.begin(), itEnd = map.end(); it != itEnd; ++it) {
+        if (it->value == this) {
+            map.remove(it);
+            break;
+        }
+    }

[tyoshino (SeeGerritForStatus), 2014/09/02 04:12:16]

I recommend that we place this close to stopParsing() call.

[kouhei (in TOK), 2014/09/02 16:17:27]

Done.

+
     if (m_responseLegacyStream && m_state != DONE)
         m_responseLegacyStream->abort();
 
@@ -1283,19 +1299,25 @@ void XMLHttpRequest::didFinishLoading(unsigned long identifier, double)
     if (m_state < HEADERS_RECEIVED)
         changeState(HEADERS_RECEIVED);
 
+    m_loaderIdentifier = identifier;
+
     if (m_responseDocumentParser) {
+        // |DocumentParser::finish()| tells the parser that we have reached end of the data.
+        // When using |HTMLDocumentParser|, which works asynchronously, we do not have the
+        // complete document just after the |DocumentParser::finish()| call.
         m_responseDocumentParser->finish();

[tyoshino (SeeGerritForStatus), 2014/09/02 04:19:19]

We are never notified of completion synchronously? If it's possible for some
cases, how about adding this to xhrPendingDocumentParserMap() before calling
finish()?

[kouhei (in TOK), 2014/09/02 16:17:27]

Great catch. Done.

-        m_responseDocumentParser = nullptr;
+        ASSERT(m_responseDocument);
 
-        m_responseDocument->implicitClose();
-
-        if (!m_responseDocument->wellFormed())
-            m_responseDocument = nullptr;
+        // Record |this| as a XHR waiting for document parse to complete, and wait for
+        // |Document::finishedParsing| to call us back in |didFinishParsingDocument| to progress state.
+        HashMap<Document*, XMLHttpRequest*>& map = xhrPendingDocumentParseMap();
+        HashMap<Document*, XMLHttpRequest*>::AddResult result = map.set(m_responseDocument.get(), this);
+        ASSERT_UNUSED(result, result.isNewEntry);
+        return;
+    }
 
-        m_parsedResponse = true;
-    } else if (m_decoder) {
+    if (m_decoder)
         m_responseText = m_responseText.concatenateWith(m_decoder->flush());
-    }
 
     if (m_responseLegacyStream)
         m_responseLegacyStream->finalize();
@@ -1303,12 +1325,42 @@ void XMLHttpRequest::didFinishLoading(unsigned long identifier, double)
     if (m_responseStream)
         m_responseStream->close();
 
+    endLoading();
+}
+
+XMLHttpRequest* XMLHttpRequest::findInstancePendingDocumentParse(Document* document)
+{
+    return xhrPendingDocumentParseMap().get(document);
+}
+
+void XMLHttpRequest::didFinishParsingDocument()
+{
+    // This should only be called when response document is parsed asynchronously.
+    ASSERT(m_responseDocumentParser);
+    ASSERT(!m_responseDocumentParser->isParsing());
+    ASSERT(!m_responseLegacyStream);
+    ASSERT(!m_responseStream);
+
+    m_responseDocumentParser = nullptr;
+    m_responseDocument->implicitClose();
+
+    if (!m_responseDocument->wellFormed())
+        m_responseDocument = nullptr;
+
+    m_parsedResponse = true;
+
+    endLoading();
+}
+
+void XMLHttpRequest::endLoading()
+{
     clearVariablesForLoading();
 
-    InspectorInstrumentation::didFinishXHRLoading(executionContext(), this, this, identifier, m_responseText, m_method, m_url, m_lastSendURL, m_lastSendLineNumber);
+    InspectorInstrumentation::didFinishXHRLoading(executionContext(), this, this, m_loaderIdentifier, m_responseText, m_method, m_url, m_lastSendURL, m_lastSendLineNumber);
 
     if (m_loader)
         m_loader = nullptr;
+    m_loaderIdentifier = 0;
 
     changeState(DONE);
 }