--- a/dom/base/Navigator.cpp
+++ b/dom/base/Navigator.cpp
@@ -580,17 +580,18 @@ Navigator::CookieEnabled()
 
   return cookieEnabled;
 }
 
 bool
 Navigator::OnLine()
 {
   if (mWindow && mWindow->GetDoc()) {
-    return !NS_IsAppOffline(mWindow->GetDoc()->NodePrincipal());
+    return !NS_IsOffline() &&
+      !NS_IsAppOffline(mWindow->GetDoc()->NodePrincipal());
   }
 
   return !NS_IsOffline();
 }
 
 NS_IMETHODIMP
 Navigator::GetBuildID(nsAString& aBuildID)
 {

--- a/dom/workers/RuntimeService.cpp
+++ b/dom/workers/RuntimeService.cpp
@@ -2615,17 +2615,17 @@ RuntimeService::Observe(nsISupports* aSu
 
     uint32_t notificationAppId = nsIScriptSecurityManager::UNKNOWN_APP_ID;
     info->GetAppId(&notificationAppId);
 
     if (appId != notificationAppId) {
       return NS_OK;
     }
 
-    SendOfflineStatusChangeEventToAllWorkers(NS_IsAppOffline(appId));
+    SendOfflineStatusChangeEventToAllWorkers(NS_IsOffline() || NS_IsAppOffline(appId));
   }
 
   NS_NOTREACHED("Unknown observer topic!");
   return NS_OK;
 }
 
 /* static */ void
 RuntimeService::WorkerPrefChanged(const char* aPrefName, void* aClosure)

--- a/netwerk/base/public/nsIIOService.idl
+++ b/netwerk/base/public/nsIIOService.idl
@@ -14,17 +14,17 @@ interface nsIFile;
  * nsIIOService provides a set of network utility functions.  This interface
  * duplicates many of the nsIProtocolHandler methods in a protocol handler
  * independent way (e.g., NewURI inspects the scheme in order to delegate
  * creation of the new URI to the appropriate protocol handler).  nsIIOService
  * also provides a set of URL parsing utility functions.  These are provided
  * as a convenience to the programmer and in some cases to improve performance
  * by eliminating intermediate data structures and interfaces.
  */
-[scriptable, uuid(bddeda3f-9020-4d12-8c70-984ee9f7935e)]
+[scriptable, uuid(2d19475d-7557-43f7-9682-0c44417b6c0f)]
 interface nsIIOService : nsISupports
 {
     /**
      * Returns a protocol handler for a given URI scheme.
      *
      * @param aScheme the URI scheme
      * @return reference to corresponding nsIProtocolHandler
      */
@@ -97,16 +97,17 @@ interface nsIIOService : nsISupports
      * 'state' must one of nsIAppOfflineInfo::{ONLINE|OFFLINE|WIFI_ONLY}.
      */
     void setAppOffline(in uint32_t appId, in long state);
 
     /**
      * Returns true if given appId is currently not allowed to make network
      * connections. It will return true if the app is in the wifi-only state
      * and we are currently on a 3G connection.
+     * The returned value does not depend on the offline state of the browser.
      */
     boolean isAppOffline(in uint32_t appId);
 
 
     /**
      * Checks if a port number is banned. This involves consulting a list of
      * unsafe ports, corresponding to network services that may be easily
      * exploitable. If the given port is considered unsafe, then the protocol

--- a/netwerk/base/src/nsIOService.cpp
+++ b/netwerk/base/src/nsIOService.cpp
@@ -1504,22 +1504,17 @@ nsIOService::SetAppOfflineInternal(uint3
     }
 
 }
 
 NS_IMETHODIMP
 nsIOService::IsAppOffline(uint32_t aAppId, bool* aResult)
 {
     NS_ENSURE_ARG(aResult);
-    *aResult = mOffline;
-
-    if (mOffline) {
-        // If the entire browser is offline, return that status
-        return NS_OK;
-    }
+    *aResult = false;
 
     if (aAppId == NECKO_NO_APP_ID ||
         aAppId == NECKO_UNKNOWN_APP_ID) {
         return NS_ERROR_NOT_AVAILABLE;
     }
 
     int32_t state;
     if (mAppsOfflineStatus.Get(aAppId, &state)) {