Lower priority of async scripts

Source/core/dom/ScriptLoader.cpp

Index: Source/core/dom/ScriptLoader.cpp
diff --git a/Source/core/dom/ScriptLoader.cpp b/Source/core/dom/ScriptLoader.cpp
index f69e0e63d362e4750b5f16bbce060813de6b7058..4dea7b47e475275550b62de50658a5a59fdaef79 100644
--- a/Source/core/dom/ScriptLoader.cpp
+++ b/Source/core/dom/ScriptLoader.cpp
@@ -65,6 +65,8 @@ ScriptLoader::ScriptLoader(Element* element, bool parserInserted, bool alreadySt
     , m_readyToBeParserExecuted(false)
     , m_willExecuteWhenDocumentFinishedParsing(false)
     , m_forceAsync(!parserInserted)
+    , m_hasAsyncAttribute(false)
+    , m_hasDeferAttribute(false)
     , m_willExecuteInOrder(false)
 {
     ASSERT(m_element);
@@ -100,6 +102,7 @@ void ScriptLoader::handleSourceAttribute(const String& sourceUrl)
 void ScriptLoader::handleAsyncAttribute()
 {
     m_forceAsync = false;

[eseidel, 2014/09/03 15:18:10]

Are these two bools related?  Should they be an enum instead?

[Pat Meenan, 2014/09/03 16:16:17]

We might be able to use just the existing m_forceAsync flag.  There was just a
bunch of logic already tied to it and it rolled in both the async and injected
patterns.  They aren't really mutually exclusive so an enum won't help.

The part that had me worried is down below at line 187 where it does:
if (wasParserInserted && !client->asyncAttributeValue())
    m_forceAsync = true;

That seems to say that for parser-injected script without the async attribute we
toggle the forceAsync flag on which seems like the opposite of what it should
be.

+    m_hasAsyncAttribute = true;
 }
 
 // Helper function
@@ -184,6 +187,9 @@ bool ScriptLoader::prepareScript(const TextPosition& scriptStartPosition, Legacy
     if (wasParserInserted && !client->asyncAttributeValue())
         m_forceAsync = true;
 
+    if (client->deferAttributeValue())
+        m_hasDeferAttribute = true;
+
     // FIXME: HTML5 spec says we should check that all children are either comments or empty text nodes.
     if (!client->hasSourceAttribute() && !m_element->hasChildren())
         return false;
@@ -267,6 +273,9 @@ bool ScriptLoader::fetchScript(const String& sourceUrl)
         if (scriptPassesCSP)
             request.setContentSecurityCheck(DoNotCheckContentSecurityPolicy);
 
+        if (!m_parserInserted || m_hasAsyncAttribute || m_hasDeferAttribute)
+            request.setExecAsync(true);
+
         m_resource = elementDocument->fetcher()->fetchScript(request);
         m_isExternalScript = true;
     }