Script streaming: Add an option to make the main thread block (wait for parsing)

Source/bindings/core/v8/ScriptStreamer.h

Index: Source/bindings/core/v8/ScriptStreamer.h
diff --git a/Source/bindings/core/v8/ScriptStreamer.h b/Source/bindings/core/v8/ScriptStreamer.h
index 78fa1cbc7e2a387bc835345646d88e676ebe6160..4bcc7f741977fbbd560cbc74461d15847bacd93d 100644
--- a/Source/bindings/core/v8/ScriptStreamer.h
+++ b/Source/bindings/core/v8/ScriptStreamer.h
@@ -82,7 +82,7 @@ public:
 
     // Called by ScriptStreamingTask when it has streamed all data to V8 and V8
     // has processed it.
-    void streamingComplete();
+    void streamingCompleteOnBackgroundThread();
 
     static void removeSmallScriptThresholdForTesting()
     {
@@ -96,8 +96,9 @@ private:
     // streamed. Non-const for testing.
     static size_t kSmallScriptThreshold;
 
-    ScriptStreamer(ScriptResource*, v8::ScriptCompiler::StreamedSource::Encoding, PendingScript::Type);
+    ScriptStreamer(ScriptResource*, v8::ScriptCompiler::StreamedSource::Encoding, PendingScript::Type, bool blockMainThreadAfterLoading);
 
+    void streamingComplete();
     void notifyFinishedToClient();
 
     static const char* startedStreamingHistogramName(PendingScript::Type);
@@ -118,7 +119,9 @@ private:
     ScriptResourceClient* m_client;
     WTF::OwnPtr<v8::ScriptCompiler::ScriptStreamingTask> m_task;
     bool m_loadingFinished; // Whether loading from the network is done.
-    bool m_parsingFinished; // Whether the V8 side processing is done.
+    // Whether the V8 side processing is done. Will be used by the main thread
+    // and the streamer thread; guarded by m_mutex.
+    bool m_parsingFinished;
     bool m_firstDataChunkReceived;
 
     // Whether the script source code should be retrieved from the Resource
@@ -130,6 +133,13 @@ private:
 
     // For recording metrics for different types of scripts separately.
     PendingScript::Type m_scriptType;
+
+    // Whether the main thread should block and wait for the parsing to complete
+    // after the load has finished. See ScriptStreamer::notifyFinished for more
+    // information.
+    bool m_blockMainThreadAfterLoading;
+    Mutex m_mutex;
+    ThreadCondition m_parsingFinishedCondition;
 };
 
 } // namespace blink