[HTML Imports] Let script of imported document running.

Source/core/html/HTMLImport.cpp

Index: Source/core/html/HTMLImport.cpp
diff --git a/Source/core/html/HTMLImport.cpp b/Source/core/html/HTMLImport.cpp
index 8e349be5c3a5688b9b61d29e9d15fb1a90672d44..8e381776003a5d7958e96048b46e47088544497e 100644
--- a/Source/core/html/HTMLImport.cpp
+++ b/Source/core/html/HTMLImport.cpp
@@ -31,6 +31,7 @@
 #include "config.h"
 #include "core/html/HTMLImport.h"
 
+#include "core/dom/Document.h"
 #include "core/html/HTMLImportsController.h"
 
 namespace WebCore {
@@ -42,4 +43,14 @@ bool HTMLImport::haveChildrenLoaded()
     return true;
 }
 
+Frame* HTMLImport::frame()
+{
+    return master()->frame();
+}
+
+Document* HTMLImport::master()
+{
+    return controller()->document();
+}
+
 } // namespace WebCore