Mark LoadContext's constructor as explicit, follow-up to bug 1009631, landed on a CLOSED TREE

docshell/base/LoadContext.h

@@ -107,7 +107,7 @@ public:
 
   // Constructor for creating a LoadContext with a given principal's appId and
   // browser flag.
-  LoadContext(nsIPrincipal* aPrincipal);
+  explicit LoadContext(nsIPrincipal* aPrincipal);
 
 private:
   ~LoadContext() {}