incantations for WebContentsPreferences::GetPreloadPath wide strings

shell/browser/web_contents_preferences.cc

@@ -61,6 +61,21 @@ bool GetAsString(const base::Value* val,
   return false;
 }
 
+#if defined(OS_WIN)
+bool GetAsString(const base::Value* val,
+                 base::FilePath::StringPieceType path,
+                 std::u16string* out) {
+  if (val) {
+    auto* found = val->FindKeyOfType(path, base::Value::Type::STRING);
+    if (found) {
+      *out = base::UTF8ToWide(found->GetString());
+      return true;
+    }
+  }
+  return false;
+}
+#endif
+
 bool GetAsInteger(const base::Value* val, base::StringPiece path, int* out) {
   if (val) {
     auto* found = val->FindKey(path);
@@ -246,6 +261,12 @@ bool WebContentsPreferences::GetPreloadPath(base::FilePath* path) const {
   } else if (GetAsString(&preference_, options::kPreloadURL, &preload_path)) {
     // Translate to file path if there is "preload-url" option.
     base::FilePath preload;
+    GURL preload_url;
+#if defined(OS_WIN)
+    preload_url = GURL(base::WideToUTF8(preload_path));
+#else
+    preload_url = GURL(preload_path);
+#endif
     if (net::FileURLToFilePath(GURL(preload_path), &preload)) {
       *path = std::move(preload);
       return true;