Set 'ResourceRequest::requestorOrigin' in Blink for more request types.

third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp b/third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp
index 9c4ad94d0bc066d6f3a534f17b09d35c6851f147..4dd89cf2fcdd3578c7a0180cd9249c655f31d28f 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoadRequest.cpp
@@ -53,10 +53,22 @@ FrameLoadRequest::FrameLoadRequest(Document* originDocument, const ResourceReque
 
     if (originDocument) {
         m_resourceRequest.setRequestorOrigin(SecurityOrigin::create(originDocument->url()));
-    } else {
-        if (m_resourceRequest.frameType() == WebURLRequest::FrameTypeTopLevel) {
-            m_resourceRequest.setRequestorOrigin(SecurityOrigin::create(resourceRequest.url()));
-        }
+        return;
+    }
+
+    // If we don't have an origin document, and we're going to throw away the response data
+    // regardless, set the requestor to a unique origin.
+    if (m_substituteData.isValid()) {
+        m_resourceRequest.setRequestorOrigin(SecurityOrigin::createUnique());
+        return;
+    }
+
+    // If we're dealing with a top-level request, use the origin of the requested URL as the initiator.
+    //
+    // TODO(mkwst): This should be `nullptr`. https://crbug.com/625969
+    if (m_resourceRequest.frameType() == WebURLRequest::FrameTypeTopLevel) {
+        m_resourceRequest.setRequestorOrigin(SecurityOrigin::create(resourceRequest.url()));
+        return;
     }
 }