import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1048131 - Remove MOZ_CAPTIVEDETECT and enable captive portal detector for all products. r=mcmanus (d2b2980c1)
- Bug 1048131 - Implement CaptivePortalService using nsICaptivePortalDetector r=mcmanus (d62c390d4)
- Bug 1048131 - Make some network events trigger a captive portal recheck r=mcmanus (8c19273f0)
- Bug 1166910 - Gecko changes for adding referrer attribute. r=hsivonen (46676ae77)
- Bug 1166910 - Referrer attribute for img tag. r=ckerschb, r=hsivonen, r=bz (f833f3e6c)
- Bug 1174913 - anchor and area referrer attributes. r=ckerschb, r=bz (f99a956be) (backend parts only)
- missing bits of Bug 1210302 - Part 1: Rename nsINetUtil.parseContentType() to parseResponseContentType(); r=mcmanus (eb8fba336)
- Bug 1210302 - Part 2: Rename NS_ParseContentType to NS_ParseResponseContentType; r=mcmanus,sicking (74f4cd98d)
- remaining bits of Bug 1210302 - Part 3: Add a NS_ParseRequestContentType API; r=mcmanus,sicking (56477b434)
- pointer style (ca5142301)
- Bug 1172109 - Name some anonymous structs to help out the analysis, r=terrence (775d17318)
- Bug 1173042 - Remove unused GCChunkSet and chunk hashing functions; r=ehoogeveen (357e0887d)
- Bug 1177778 - Allow HeapPtr destruction while shutting down the GC r=terrence (793654cb2)
- Bug 1181306 - Skip compacting phase when finishing an incremental GC non-incrementally r=terrence (7547c11ad)
- Bug 1162961 - Fix logspam in mochitest-dt by passing the URL along in network progress events;r=past (3b4c9048f)
- Bug 1149235 part 1. Move nsScriptLoadRequest into nsScriptLoader.h. r=sicking (df56a3e9d)
- Bug 1149235 part 2. Switch to using linked lists for nsScriptLoadRequest. r=sicking (7a0536b53)
- Bug 1149235 part 3. Store async requests in the scriptloader in two lists, so we don't have to grovel about looking for loaded ones. r=sicking (db45689c6)
- Bug 1154598. Keep better track of our script requests. r=smaug (a2232a237)
- Bug 1157995 - Tell the cycle collector about Navigator::mMediaDevices. r=smaug (9a9147bdf)
- Bug 1181619. Make sure we've entered a microtask before we call nsJSUtils::EvaluateString, and put those microtasks outside the relevant AutoEntryScripts so we report any possible exceptions before doing the microtask checkpoint. r=bholley (851e371ac)

parser/html/nsHtml5TreeOpExecutor.cpp

@@ -947,13 +947,25 @@ void
 nsHtml5TreeOpExecutor::PreloadImage(const nsAString& aURL,
                                     const nsAString& aCrossOrigin,
                                     const nsAString& aSrcset,
-                                    const nsAString& aSizes)
+                                    const nsAString& aSizes,
+                                    const nsAString& aImageReferrerPolicy)
 {
   nsCOMPtr<nsIURI> baseURI = BaseURIForPreload();
   nsCOMPtr<nsIURI> uri = mDocument->ResolvePreloadImage(baseURI, aURL, aSrcset,
                                                         aSizes);
   if (uri && ShouldPreloadURI(uri)) {
-    mDocument->MaybePreLoadImage(uri, aCrossOrigin, mSpeculationReferrerPolicy);
+    // 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);
+    if (referrerAttributeEnabled) {
+      mozilla::net::ReferrerPolicy imageReferrerPolicy = mozilla::net::ReferrerPolicyFromString(aImageReferrerPolicy);
+      if (imageReferrerPolicy != mozilla::net::RP_Unset) {
+        referrerPolicy = imageReferrerPolicy;
+      }
+    }
+
+    mDocument->MaybePreLoadImage(uri, aCrossOrigin, referrerPolicy);
   }
 }