Set the target type when creating the request for main resource

public/platform/WebURLRequest.h

Index: public/platform/WebURLRequest.h
diff --git a/public/platform/WebURLRequest.h b/public/platform/WebURLRequest.h
index 7d9e4dcda03fa69796189c4431bfee4229f30c29..4539aed636f9cefebe09b0ab5a39f5414078b076 100644
--- a/public/platform/WebURLRequest.h
+++ b/public/platform/WebURLRequest.h
@@ -113,6 +113,9 @@ public:
     BLINK_PLATFORM_EXPORT void reset();
     BLINK_PLATFORM_EXPORT void assign(const WebURLRequest&);
 
+    // Initializes the TargetType and the Priority for main resources
+    BLINK_PLATFORM_EXPORT void initializeForMainResource(bool isMainFrame);
+
     BLINK_PLATFORM_EXPORT bool isNull() const;
 
     BLINK_PLATFORM_EXPORT WebURL url() const;