Bug 1223838 - enable perElementReferrer by default. r=hsivonen

dom/base/Element.cpp

@@ -3772,7 +3772,7 @@ Element::FontSizeInflation()
 net::ReferrerPolicy
 Element::GetReferrerPolicyAsEnum()
 {
-  if (Preferences::GetBool("network.http.enablePerElementReferrer", false) &&
+  if (Preferences::GetBool("network.http.enablePerElementReferrer", true) &&
       IsHTMLElement()) {
     const nsAttrValue* referrerValue = GetParsedAttr(nsGkAtoms::referrerpolicy);
     if (referrerValue && referrerValue->Type() == nsAttrValue::eEnum) {

modules/libpref/init/all.js

@@ -1413,7 +1413,7 @@ pref("network.http.referer.XOriginPolicy", 0);
 pref("network.http.sendSecureXSiteReferrer", true);
 
 // Controls whether referrer attributes in <a>, <img>, <area>, and <iframe> are honoured
-pref("network.http.enablePerElementReferrer", false);
+pref("network.http.enablePerElementReferrer", true);
 
 // Maximum number of consecutive redirects before aborting.
 pref("network.http.redirection-limit", 20);

parser/html/nsHtml5TreeOpExecutor.cpp

@@ -950,7 +950,7 @@ nsHtml5TreeOpExecutor::PreloadImage(const nsAString& aURL,
     // use document wide referrer policy
     mozilla::net::ReferrerPolicy referrerPolicy = mSpeculationReferrerPolicy;
     // if enabled in preferences, use the referrer attribute from the image, if provided
-    bool referrerAttributeEnabled = Preferences::GetBool("network.http.enablePerElementReferrer", false);
+    bool referrerAttributeEnabled = Preferences::GetBool("network.http.enablePerElementReferrer", true);
     if (referrerAttributeEnabled) {
       mozilla::net::ReferrerPolicy imageReferrerPolicy = mozilla::net::ReferrerPolicyFromString(aImageReferrerPolicy);
       if (imageReferrerPolicy != mozilla::net::RP_Unset) {