jonah feedback

fml/status_or.h

@@ -11,7 +11,22 @@
 
 namespace fml {
 
-/// TODO(): Replace with absl::StatusOr.
+// TODO(https://github.com/flutter/flutter/issues/134741): Replace with
+// absl::StatusOr.
+/// Represents a union type of an object of type `T` and an fml::Status.
+///
+/// This is often used as a replacement for C++ exceptions where a function that
+/// could fail may return an error or a result. These are typically used for
+/// errors that are meant to be recovered from. If there is no recovery
+/// available `FML_CHECK` is more appropriate.
+///
+/// Example:
+/// StatusOr<int> div(int n, int d) {
+///   if (d == 0) {
+///     return Status(StatusCode::kFailedPrecondition, "div by zero");
+///   }
+///   return n / d;
+/// }
 template <typename T>
 class StatusOr {
  public:

lib/ui/painting.dart

@@ -1941,7 +1941,7 @@ base class _Image extends NativeFieldWrapperClass1 {
       if (encoded != null) {
         completer.complete(encoded.buffer.asByteData());
       } else {
-        completer.completeError(Exception(error ?? 'unknown error'));
+        completer.completeError(Exception(error ?? 'Unknown exception.'));
       }
     });
     if (syncError != null) {

lib/ui/painting/image_encoding_impeller.cc

@@ -65,7 +65,7 @@ void DoConvertImageToRasterImpeller(
       fml::SyncSwitch::Handlers()
           .SetIfTrue([&encode_task] {
             encode_task(
-                fml::Status(fml::StatusCode::kUnavailable, "gpu unavailable"));
+                fml::Status(fml::StatusCode::kUnavailable, "GPU unavailable."));
           })
           .SetIfFalse([&dl_image, &encode_task, &impeller_context] {
             ImageEncodingImpeller::ConvertDlImageToSkImage(
@@ -82,14 +82,12 @@ void ImageEncodingImpeller::ConvertDlImageToSkImage(
   auto texture = dl_image->impeller_texture();
 
   if (impeller_context == nullptr) {
-    FML_LOG(ERROR) << "Impeller context was null.";
     encode_task(fml::Status(fml::StatusCode::kFailedPrecondition,
                             "Impeller context was null."));
     return;
   }
 
   if (texture == nullptr) {
-    FML_LOG(ERROR) << "Image was null.";
     encode_task(
         fml::Status(fml::StatusCode::kFailedPrecondition, "Image was null."));
     return;
@@ -99,14 +97,12 @@ void ImageEncodingImpeller::ConvertDlImageToSkImage(
   auto color_type = ToSkColorType(texture->GetTextureDescriptor().format);
 
   if (dimensions.isEmpty()) {
-    FML_LOG(ERROR) << "Image dimensions were empty.";
     encode_task(fml::Status(fml::StatusCode::kFailedPrecondition,
                             "Image dimensions were empty."));
     return;
   }
 
   if (!color_type.has_value()) {
-    FML_LOG(ERROR) << "Failed to get color type from pixel format.";
     encode_task(fml::Status(fml::StatusCode::kUnimplemented,
                             "Failed to get color type from pixel format."));
     return;