Rename entry_point to entrypoint (#152)

* Rename entry_point to entrypoint

* Empty values are allowed

Author: swift-kim

shell/platform/tizen/flutter_tizen.cc

@@ -40,7 +40,7 @@ FlutterDesktopEngineRef FlutterDesktopRunEngine(
         window_properties.height, window_properties.transparent,
         window_properties.focusable);
   }
-  if (!engine->RunEngine(engine_properties.entry_point)) {
+  if (!engine->RunEngine(engine_properties.entrypoint)) {
     FT_LOG(Error) << "Failed to start the Flutter engine.";
     return nullptr;
   }

shell/platform/tizen/public/flutter_tizen.h

@@ -55,13 +55,13 @@ typedef struct {
   const char** switches;
   // The number of elements in |switches|.
   size_t switches_count;
-  // The optional entry point in the Dart project, if the entry point is null,
-  // defaults to main().
-  const char* entry_point;
+  // The optional entrypoint in the Dart project. If the value is null or
+  // empty, defaults to main().
+  const char* entrypoint;
   // Number of elements in the array passed in as dart_entrypoint_argv.
   int dart_entrypoint_argc;
   // Array of Dart entrypoint arguments. This is deep copied during the call
-  // to FlutterDesktopEngineCreate.
+  // to FlutterDesktopRunEngine.
   const char** dart_entrypoint_argv;
 } FlutterDesktopEngineProperties;