Bug 657480: Clean up after TelemetryPing.js r=mak

toolkit/components/telemetry/TelemetryPing.js

@@ -235,12 +235,25 @@ TelemetryPing.prototype = {
       let idleService = Cc["@mozilla.org/widget/idleservice;1"].
                         getService(Ci.nsIIdleService);
       idleService.addIdleObserver(self, TELEMETRY_INTERVAL);
-      Services.obs.addObserver(self, "idle-daily", null);
+      Services.obs.addObserver(self, "idle-daily", false);
+      Services.obs.addObserver(self, "profile-before-change", false);
       self.gatherMemory();
+      delete self._timer
     }
     this._timer.initWithCallback(timerCallback, TELEMETRY_DELAY, Ci.nsITimer.TYPE_ONE_SHOT);
   },
 
+  /** 
+   * Remove observers to avoid leaks
+   */
+  uninstall: function uninstall() {
+    let idleService = Cc["@mozilla.org/widget/idleservice;1"].
+                      getService(Ci.nsIIdleService);
+    idleService.removeIdleObserver(this, TELEMETRY_INTERVAL);
+    Services.obs.removeObserver(this, "idle-daily");
+    Services.obs.removeObserver(this, "profile-before-change");
+  },
+
   /**
    * This observer drives telemetry.
    */
@@ -252,6 +265,9 @@ TelemetryPing.prototype = {
     case "profile-after-change":
       this.setup();
       break;
+    case "profile-before-change":
+      this.uninstall();
+      break;
     case "idle":
       this.gatherMemory();
       break;