chore: resolve Object langAliases in function argument types

Inner Objects nested inside function-typed arguments are not visited
by createClassesAndEnums, so the api generator never set customType
for them and had to fall back to a hardcoded jsonPath switch (the
Screencast.start.onFrame -> Consumer<ScreencastFrame> case).

Have convertBuiltinType resolve the Java type name from the inner
Object's langAliases when no customType is set, and drop the hardcoded
onFrame case. This works once microsoft/playwright adds alias-java
for the onFrame Object (already proposed upstream).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: yury-s

tools/api-generator/src/main/java/com/microsoft/playwright/tools/ApiGenerator.java

@@ -506,6 +506,12 @@ private String convertBuiltinType(JsonObject jsonType) {
       if (customType != null) {
         return customType;
       }
+      // Inner Objects (e.g. function arguments) are not visited by createClassesAndEnums,
+      // so resolve their Java type name from langAliases here.
+      String alias = javaAlias(jsonType);
+      if (alias != null) {
+        return alias;
+      }
       return "Map<" + convertTemplateParams(jsonType) + ">";
     }
     if ("Map".equals(name)) {
@@ -525,9 +531,6 @@ private String convertBuiltinType(JsonObject jsonType) {
       if ("WebSocketRoute.onClose.handler".equals(jsonPath)) {
         return "BiConsumer<Integer, String>";
       }
-      if ("Screencast.start.options.onFrame".equals(jsonPath)) {
-        return "Consumer<ScreencastFrame>";
-      }
       if (jsonType.getAsJsonArray("args").size() == 1) {
         String paramType = convertBuiltinType(jsonType.getAsJsonArray("args").get(0).getAsJsonObject());
         if (!jsonType.has("returnType") || jsonType.get("returnType").isJsonNull()) {