Instrument parser blocking script execution time.

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

Index: third_party/WebKit/Source/core/dom/ScriptLoader.h
diff --git a/third_party/WebKit/Source/core/dom/ScriptLoader.h b/third_party/WebKit/Source/core/dom/ScriptLoader.h
index 24f3ebd7e0b67ad6d76412f07751c1a0f73a65fe..b8f3d9533c7c76b1bbbe17e27340650f000104bb 100644
--- a/third_party/WebKit/Source/core/dom/ScriptLoader.h
+++ b/third_party/WebKit/Source/core/dom/ScriptLoader.h
@@ -23,9 +23,11 @@
 
 #include "core/CoreExport.h"
 #include "core/dom/PendingScript.h"
+#include "core/dom/ScriptRunner.h"
 #include "core/fetch/FetchRequest.h"
 #include "core/fetch/ResourceClient.h"
 #include "core/fetch/ScriptResource.h"
+#include "wtf/Optional.h"
 #include "wtf/text/TextPosition.h"
 #include "wtf/text/WTFString.h"
 
@@ -97,6 +99,7 @@ private:
     void logScriptMimetype(ScriptResource*, LocalFrame*, String);
 
     bool fetchScript(const String& sourceUrl, FetchRequest::DeferOption);
+    bool doExecuteScript(const ScriptSourceCode&);
 
     ScriptLoaderClient* client() const;
 
@@ -116,11 +119,15 @@ private:
     bool m_haveFiredLoad : 1;
     bool m_willBeParserExecuted : 1; // Same as "The parser will handle executing the script."
     bool m_readyToBeParserExecuted : 1;
-    bool m_willExecuteInOrder : 1;
     bool m_willExecuteWhenDocumentFinishedParsing : 1;
     bool m_forceAsync : 1;
     const bool m_createdDuringDocumentWrite : 1;
 
+    // Async scripts may either execute as their load completes, or 'in
+    // order'. See http://www.html5rocks.com/en/tutorials/speed/script-loading/
+    // for more information.
+    WTF::Optional<ScriptRunner::ExecutionType> m_asyncExecType;

[kouhei (in TOK), 2016/08/26 10:01:48]

Would you add another ExecutionType instead of WTF::Optional?

[Bryan McQuade, 2016/08/28 21:09:23]

Sure. I also renamed the enum to AsyncExecutionType, since it's specific to
async scripts, and fixed the enum naming to match the blink style guide
(AsyncExecution rather than ASYNC_EXECUTION). PTAL, thanks!

+
     Member<PendingScript> m_pendingScript;
 };