Bug 1175736 - Implement the iframe referrer attribute. r=ckerschb, r=bz

dom/base/nsFrameLoader.cpp

@@ -378,7 +378,19 @@ nsFrameLoader::ReallyStartLoadingInternal()
     }
   }
 
-  loadInfo->SetReferrerPolicy(mOwnerContent->OwnerDoc()->GetReferrerPolicy());
+  // get referrer policy for this iframe:
+  // first load document wide policy, then
+  // load iframe referrer attribute if enabled in preferences
+  // per element referrer overrules document wide referrer if enabled
+  net::ReferrerPolicy referrerPolicy = mOwnerContent->OwnerDoc()->GetReferrerPolicy();
+  HTMLIFrameElement* iframe = HTMLIFrameElement::FromContent(mOwnerContent);
+  if (iframe) {
+    net::ReferrerPolicy iframeReferrerPolicy = iframe->GetReferrerPolicy();
+    if (iframeReferrerPolicy != net::RP_Unset) {
+      referrerPolicy = iframeReferrerPolicy;
+    }
+  }
+  loadInfo->SetReferrerPolicy(referrerPolicy);
 
   // Default flags:
   int32_t flags = nsIWebNavigation::LOAD_FLAGS_NONE;

dom/html/HTMLIFrameElement.h

@@ -159,6 +159,15 @@ public:
   {
     SetHTMLAttr(nsGkAtoms::marginheight, aMarginHeight, aError);
   }
+  void SetReferrer(const nsAString& aReferrer, ErrorResult& aError)
+  {
+    SetHTMLAttr(nsGkAtoms::referrer, aReferrer, aError);
+  }
+  void GetReferrer(nsAString& aReferrer)
+  {
+    GetHTMLAttr(nsGkAtoms::referrer, aReferrer);
+  }
+
   nsIDocument* GetSVGDocument()
   {
     return GetContentDocument();

dom/webidl/HTMLIFrameElement.webidl

@@ -26,6 +26,8 @@ interface HTMLIFrameElement : HTMLElement {
            attribute DOMString width;
   [SetterThrows, Pure]
            attribute DOMString height;
+  [SetterThrows, Pure, Pref="network.http.enablePerElementReferrer"]
+           attribute DOMString referrer;
   readonly attribute Document? contentDocument;
   readonly attribute WindowProxy? contentWindow;
 };