FPS counter

Added toggle to enable an fps counter for the onroad UI and the current displayed camera.

selfdrive/ui/qt/onroad.h

@@ -15,6 +15,7 @@ const int btn_size = 192;
 const int img_size = (btn_size / 4) * 3;
 
 // FrogPilot global variables
+static double fps;
 
 // ***** onroad widgets *****
 class OnroadAlerts : public QWidget {
@@ -197,10 +198,17 @@ private:
   QWidget *map = nullptr;
   QHBoxLayout* split;
 
+  // FrogPilot widgets
+  void updateFPSCounter();
+
   // FrogPilot variables
   UIScene &scene;
   Params paramsMemory{"/dev/shm/params"};
 
+  double avgFPS;
+  double maxFPS = 0.0;
+  double minFPS = 99.9;
+
   QPoint timeoutPoint = QPoint(420, 69);
   QTimer clickTimer;