Increase the mouse scroll speed (flutter-tizen#73)

* Increase mouse wheel scroll speed

* Suppress error message on app launch

Author: swift-kim

shell/platform/tizen/flutter_tizen.cc

@@ -215,25 +215,25 @@ void FlutterRegisterViewFactory(
 
 FlutterDesktopTextureRegistrarRef FlutterDesktopRegistrarGetTextureRegistrar(
     FlutterDesktopPluginRegistrarRef registrar) {
-  FT_LOGE("Tizen DesktopTexture support is not implemented yet.");
+  FT_UNIMPLEMENTED();
   return nullptr;
 }
 
 int64_t FlutterDesktopTextureRegistrarRegisterExternalTexture(
     FlutterDesktopTextureRegistrarRef texture_registrar,
     const FlutterDesktopTextureInfo* texture_info) {
-  FT_LOGE("Tizen DesktopTexture support is not implemented yet.");
+  FT_UNIMPLEMENTED();
   return -1;
 }
 
 bool FlutterDesktopTextureRegistrarUnregisterExternalTexture(
     FlutterDesktopTextureRegistrarRef texture_registrar, int64_t texture_id) {
-  FT_LOGE("Tizen DesktopTexture support is not implemented yet.");
+  FT_UNIMPLEMENTED();
   return false;
 }
 
 bool FlutterDesktopTextureRegistrarMarkExternalTextureFrameAvailable(
     FlutterDesktopTextureRegistrarRef texture_registrar, int64_t texture_id) {
-  FT_LOGE("Tizen DesktopTexture support is not implemented yet.");
+  FT_UNIMPLEMENTED();
   return false;
 }

shell/platform/tizen/touch_event_handler.cc

@@ -63,8 +63,8 @@ void TouchEventHandler::SendFlutterPointerEvent(FlutterPointerPhase phase,
   if (scroll_delta_x != 0 || scroll_delta_y != 0) {
     event.signal_kind = kFlutterPointerSignalKindScroll;
   }
-  event.scroll_delta_x = scroll_delta_x;
-  event.scroll_delta_y = scroll_delta_y;
+  event.scroll_delta_x = scroll_delta_x * 2;
+  event.scroll_delta_y = scroll_delta_y * 2;
   event.timestamp = timestamp * 1000;
   FlutterEngineSendPointerEvent(engine_->flutter_engine, &event, 1);
 }