Script-based imports should basically work

sky/engine/core/dom/DocumentParser.h

Index: sky/engine/core/dom/DocumentParser.h
diff --git a/sky/engine/core/dom/DocumentParser.h b/sky/engine/core/dom/DocumentParser.h
index af6feb5575380bf274e81996915f8d7227646964..3141925fd6981137513be21baede7a4aa55c87d1 100644
--- a/sky/engine/core/dom/DocumentParser.h
+++ b/sky/engine/core/dom/DocumentParser.h
@@ -24,6 +24,7 @@
 #ifndef DocumentParser_h
 #define DocumentParser_h
 
+#include "base/callback_forward.h"
 #include "mojo/public/cpp/system/core.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
@@ -41,7 +42,8 @@ class DocumentParser : public RefCounted<DocumentParser> {
 public:
     virtual ~DocumentParser();
 
-    virtual void parse(mojo::ScopedDataPipeConsumerHandle) = 0;
+    virtual void parse(mojo::ScopedDataPipeConsumerHandle,
+                       const base::Closure& completionCallback) = 0;
 
     virtual TextPosition textPosition() const = 0;
     virtual void executeScriptsWaitingForResources() = 0;