Bug 742780 follow-up: unbreak RIL and Wifi. r=mrbkap

dom/system/gonk/systemlibs.js

@@ -5,7 +5,10 @@
 const SYSTEM_PROPERTY_KEY_MAX = 32;
 const SYSTEM_PROPERTY_VALUE_MAX = 92;
 
-const DEBUG=false;
+// We leave this as 'undefined' instead of setting it to 'false'. That
+// way a file that includes us can have it defined already without us
+// overriding the value here.
+let DEBUG;
 
 /**
  * Expose some system-level functions.

dom/wifi/WifiWorker.js

@@ -10,7 +10,7 @@ const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
-const DEBUG = false; // set to false to suppress debug messages
+const DEBUG = false; // set to true to show debug messages
 
 const WIFIWORKER_CONTRACTID = "@mozilla.org/wifi/worker;1";
 const WIFIWORKER_CID        = Components.ID("{a14e8977-d259-433a-a88d-58dd44657e5b}");

dom/wifi/wifi_worker.js

@@ -13,7 +13,7 @@ var hwaddr = ctypes.uint8_t.array(6)();
 var len = ctypes.size_t();
 var ints = ctypes.int.array(8)();
 
-const DEBUG = false;
+let DEBUG = false;
 
 let debug;
 if (DEBUG) {