backout bug 157123, it caused crasher bug 160824

a=asa

layout/xul/base/src/nsRepeatService.cpp

@@ -46,7 +46,7 @@
 
 #if defined(XP_MAC) || defined(XP_MACOSX)
 #define INITAL_REPEAT_DELAY 250
-#define REPEAT_DELAY        25
+#define REPEAT_DELAY        10
 #else
 #define INITAL_REPEAT_DELAY 250
 #define REPEAT_DELAY        50
@@ -92,14 +92,14 @@ void nsRepeatService::Start(nsITimerCallback* aCallback)
   mRepeatTimer = do_CreateInstance("@mozilla.org/timer;1", &rv);
 
   if (NS_OK == rv)  {
-    mRepeatTimer->Init(this, INITAL_REPEAT_DELAY, PR_TRUE, NS_TYPE_REPEATING_SLACK);
-    mFirstCall = PR_TRUE;
+    mRepeatTimer->Init(this, INITAL_REPEAT_DELAY);
   }
 
 }
 
 void nsRepeatService::Stop()
 {
+  //printf("Stopping repeat timer\n");
   if (mRepeatTimer) {
      mRepeatTimer->Cancel();
      mRepeatTimer = nsnull;
@@ -109,14 +109,19 @@ void nsRepeatService::Stop()
 
 NS_IMETHODIMP_(void) nsRepeatService::Notify(nsITimer *timer)
 {
+   // if the repeat delay is the initial one reset it.
+  if (mRepeatTimer) {
+     mRepeatTimer->Cancel();
+  }
+
   // do callback
   if (mCallback)
     mCallback->Notify(timer);
 
   // start timer again.
-  if (mFirstCall) {
-     mRepeatTimer->SetDelay(REPEAT_DELAY);
-     mFirstCall = PR_FALSE;
+  if (mRepeatTimer) {
+     mRepeatTimer = do_CreateInstance("@mozilla.org/timer;1");
+     mRepeatTimer->Init(this, REPEAT_DELAY);
   }
 
 }