[Impeller] Apply the Windows friendly path solution for remaining ImpellerC paths

impeller/compiler/impellerc_main.cc

@@ -77,10 +77,8 @@ bool Main(const fml::CommandLine& command_line) {
   reflector_options.entry_point_name = options.entry_point_name;
   reflector_options.shader_name =
       InferShaderNameFromPath(switches.source_file_name);
-  reflector_options.header_file_name =
-      ToUtf8(std::filesystem::path{switches.reflection_header_name}
-                 .filename()
-                 .native());
+  reflector_options.header_file_name = Utf8FromPath(
+      std::filesystem::path{switches.reflection_header_name}.filename());
 
   // Generate SkSL if needed.
   std::shared_ptr<fml::Mapping> sksl_mapping;

impeller/compiler/switches.cc

@@ -100,7 +100,7 @@ static SourceType SourceTypeFromCommandLine(
 Switches::Switches(const fml::CommandLine& command_line)
     : target_platform(TargetPlatformFromCommandLine(command_line)),
       working_directory(std::make_shared<fml::UniqueFD>(fml::OpenDirectory(
-          ToUtf8(std::filesystem::current_path().native()).c_str(),
+          Utf8FromPath(std::filesystem::current_path()).c_str(),
           false,  // create if necessary,
           fml::FilePermission::kRead))),
       source_file_name(command_line.GetOptionValueWithDefault("input", "")),

impeller/compiler/types.cc

@@ -8,6 +8,7 @@
 #include <sstream>
 
 #include "flutter/fml/logging.h"
+#include "impeller/compiler/utilities.h"
 
 namespace impeller {
 namespace compiler {
@@ -77,7 +78,7 @@ std::string EntryPointFunctionNameFromSourceName(const std::string& file_name,
                                                  SourceType type) {
   std::stringstream stream;
   std::filesystem::path file_path(file_name);
-  stream << ToUtf8(file_path.stem().native()) << "_";
+  stream << Utf8FromPath(file_path.stem()) << "_";
   switch (type) {
     case SourceType::kUnknown:
       stream << "unknown";
@@ -253,15 +254,6 @@ std::string TargetPlatformSLExtension(TargetPlatform platform) {
   FML_UNREACHABLE();
 }
 
-std::string ToUtf8(const std::wstring& wstring) {
-  std::wstring_convert<std::codecvt_utf8<wchar_t>> myconv;
-  return myconv.to_bytes(wstring);
-}
-
-std::string ToUtf8(const std::string& string) {
-  return string;
-}
-
 bool TargetPlatformIsOpenGL(TargetPlatform platform) {
   switch (platform) {
     case TargetPlatform::kOpenGLES:

impeller/compiler/types.h

@@ -67,9 +67,5 @@ spv::ExecutionModel ToExecutionModel(SourceType type);
 spirv_cross::CompilerMSL::Options::Platform TargetPlatformToMSLPlatform(
     TargetPlatform platform);
 
-std::string ToUtf8(const std::wstring& wstring);
-
-std::string ToUtf8(const std::string& string);
-
 }  // namespace compiler
 }  // namespace impeller