Bug 780346: Add a sample label to refresh driver. irl-r=mattwoodrow

layout/base/nsRefreshDriver.cpp

@@ -24,6 +24,7 @@
 #include "nsContentUtils.h"
 #include "mozilla/Preferences.h"
 #include "nsIViewManager.h"
+#include "sampler.h"
 
 using mozilla::TimeStamp;
 using mozilla::TimeDuration;
@@ -298,6 +299,8 @@ NS_IMPL_ISUPPORTS1(nsRefreshDriver, nsITimerCallback)
 NS_IMETHODIMP
 nsRefreshDriver::Notify(nsITimer *aTimer)
 {
+  SAMPLE_LABEL("nsRefreshDriver", "Notify");
+
   NS_PRECONDITION(!mFrozen, "Why are we notified while frozen?");
   NS_PRECONDITION(mPresContext, "Why are we notified after disconnection?");
   NS_PRECONDITION(!nsContentUtils::GetCurrentJSContext(),