Make it possible to set the HTTP origin header from content

Source/platform/network/ResourceRequest.h

Index: Source/platform/network/ResourceRequest.h
diff --git a/Source/platform/network/ResourceRequest.h b/Source/platform/network/ResourceRequest.h
index cb1e7c5a304ac3ff2ce127a54be4f5134dc570e2..0f6b023d51a42eecef96cde5f9835d3166df4c9f 100644
--- a/Source/platform/network/ResourceRequest.h
+++ b/Source/platform/network/ResourceRequest.h
@@ -146,6 +146,7 @@ public:
     const AtomicString& httpOrigin() const { return httpHeaderField("Origin"); }
     void setHTTPOrigin(const AtomicString& httpOrigin) { setHTTPHeaderField("Origin", httpOrigin); }
     void clearHTTPOrigin();
+    void addHTTPOriginIfNeeded(const AtomicString& origin);
 
     const AtomicString& httpUserAgent() const { return httpHeaderField("User-Agent"); }
     void setHTTPUserAgent(const AtomicString& httpUserAgent) { setHTTPHeaderField("User-Agent", httpUserAgent); }