GUIInvoke takes a QObject* to avoid callbacks after object lifetime

* The GUIInvoke object takes a QObject, and uses QPointer to check that
  it hasn't been deleted when the callback fires. This prevents delayed
  callbacks from executing after the object has been deleted and
  crashing.
* In most cases the pointer is just 'this'.

qrenderdoc/Windows/PerformanceCounterViewer.cpp

@@ -215,7 +215,7 @@ void PerformanceCounterViewer::CaptureCounters()
 
     const rdcarray<CounterResult> results = controller->FetchCounters(counters);
 
-    GUIInvoke::call([this, results, counterDescriptions, counterIndex]() -> void {
+    GUIInvoke::call(this, [this, results, counterDescriptions, counterIndex]() {
       ui->counterResults->clear();
 
       QStringList headers;