Teach HistoryItem about a request's initiator.

third_party/WebKit/Source/core/loader/HistoryItem.h

Index: third_party/WebKit/Source/core/loader/HistoryItem.h
diff --git a/third_party/WebKit/Source/core/loader/HistoryItem.h b/third_party/WebKit/Source/core/loader/HistoryItem.h
index 174f0546f23448b5f71b6d5f34348b5d06f131b5..5b53ca8d5b2c7a10671defcf1ef3646a0561e4e4 100644
--- a/third_party/WebKit/Source/core/loader/HistoryItem.h
+++ b/third_party/WebKit/Source/core/loader/HistoryItem.h
@@ -43,6 +43,7 @@ class DocumentState;
 class EncodedFormData;
 class KURL;
 class ResourceRequest;
+class SecurityOrigin;
 
 class CORE_EXPORT HistoryItem final : public GarbageCollectedFinalized<HistoryItem> {
 public:
@@ -56,6 +57,7 @@ public:
     KURL url() const;
 
     const Referrer& referrer() const;
+    PassRefPtr<SecurityOrigin> requestorOrigin() const;
     const String& target() const;
 
     EncodedFormData* formData();
@@ -78,6 +80,7 @@ public:
     void setURL(const KURL&);
     void setURLString(const String&);
     void setReferrer(const Referrer&);
+    void setRequestorOrigin(PassRefPtr<SecurityOrigin>);
     void setTarget(const String&);
 
     void setStateObject(PassRefPtr<SerializedScriptValue>);
@@ -105,6 +108,7 @@ private:
 
     String m_urlString;
     Referrer m_referrer;
+    String m_requestorOrigin;
     String m_target;
 
     FloatPoint m_visualViewportScrollPoint;