2 files changed, 18 insertions, 0 deletions
diff --git a/toolkit/mozapps/extensions/AddonPathService.cpp b/toolkit/mozapps/extensions/AddonPathService.cpp
index 006149100..ddfdbe817 100644
--- a/toolkit/mozapps/extensions/AddonPathService.cpp
+++ b/toolkit/mozapps/extensions/AddonPathService.cpp
@@ -128,6 +128,16 @@ AddonPathService::InsertPath(const nsAString& path, const nsAString& addonIdStri
   return NS_OK;
 }
 
+NS_IMETHODIMP
+AddonPathService::MapURIToAddonId(nsIURI* aURI, nsAString& addonIdString)
+{
+  if (JSAddonId* id = MapURIToAddonID(aURI)) {
+    JSFlatString* flat = JS_ASSERT_STRING_IS_FLAT(JS::StringOfAddonId(id));
+    AssignJSFlatString(addonIdString, flat);
+  }
+  return NS_OK;
+}
+
 static nsresult
 ResolveURI(nsIURI* aURI, nsAString& out)
 {
diff --git a/toolkit/mozapps/extensions/amIAddonPathService.idl b/toolkit/mozapps/extensions/amIAddonPathService.idl
index 863689858..9c9197a61 100644
--- a/toolkit/mozapps/extensions/amIAddonPathService.idl
+++ b/toolkit/mozapps/extensions/amIAddonPathService.idl
@@ -5,6 +5,8 @@
 
 #include "nsISupports.idl"
 
+interface nsIURI;
+
 /**
  * This service maps file system paths where add-ons reside to the ID
  * of the add-on. Paths are added by the add-on manager. They can
@@ -26,4 +28,10 @@ interface amIAddonPathService : nsISupports
    * associated with the given add-on ID.
    */
   void insertPath(in AString path, in AString addonId);
+
+  /**
+   * Given a URI to a file, return the ID of the add-on that the file belongs
+   * to. Returns an empty string if there is no add-on there.
+   */
+  AString mapURIToAddonId(in nsIURI aURI);
 };