include optional

Author: Kaushik Iska

shell/platform/darwin/ios/framework/Source/FlutterEngine.mm

@@ -452,9 +452,8 @@ - (BOOL)createShell:(NSString*)entrypoint libraryURI:(NSString*)libraryURI {
   // initialized.
   fml::MessageLoop::EnsureInitializedForCurrentThread();
 
-  flutter::ThreadHost::Type threadHostType = flutter::ThreadHost::Type::UI |
-                                             flutter::ThreadHost::Type::GPU |
-                                             flutter::ThreadHost::Type::IO;
+  uint32_t threadHostType = flutter::ThreadHost::Type::UI | flutter::ThreadHost::Type::GPU |
+                            flutter::ThreadHost::Type::IO;
   bool profilerEnabled = false;
 #if (FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG) || \
     (FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_PROFILE)

shell/profiling/sampling_profiler.h

@@ -7,6 +7,7 @@
 
 #include <functional>
 #include <memory>
+#include <optional>
 
 #include "flutter/fml/task_runner.h"
 #include "flutter/fml/trace_event.h"