[Extensions Bindings] Allow custom hooks to return values, throw

extensions/renderer/api_binding_hooks.cc

Index: extensions/renderer/api_binding_hooks.cc
diff --git a/extensions/renderer/api_binding_hooks.cc b/extensions/renderer/api_binding_hooks.cc
index 9d479b431636e99c2b8fc65274cbc2fd4076ba42..b4c93ab9eb42654c3cfc4f8f5cd22c0bcba54dcc 100644
--- a/extensions/renderer/api_binding_hooks.cc
+++ b/extensions/renderer/api_binding_hooks.cc
@@ -187,13 +187,14 @@ APIBindingHooks::RequestResult APIBindingHooks::HandleRequest(
     v8::Local<v8::Context> context,
     const APISignature* signature,
     std::vector<v8::Local<v8::Value>>* arguments,
-    const ArgumentSpec::RefMap& type_refs) {
+    const ArgumentSpec::RefMap& type_refs,
+    v8::Local<v8::Value>* return_value) {
   // Easy case: a native custom hook.
   auto request_hooks_iter = request_hooks_.find(method_name);
   if (request_hooks_iter != request_hooks_.end()) {
     RequestResult result =
         request_hooks_iter->second.Run(
-            signature, context, arguments, type_refs);
+            signature, context, arguments, type_refs, return_value);
     // Right now, it doesn't make sense to register a request handler that
     // doesn't handle the request.
     DCHECK_NE(RequestResult::NOT_HANDLED, result);
@@ -244,8 +245,15 @@ APIBindingHooks::RequestResult APIBindingHooks::HandleRequest(
     if (!success)
       return RequestResult::INVALID_INVOCATION;
 
-    run_js_.Run(handle_request, context, parsed_v8_args.size(),
-                parsed_v8_args.data());
+    v8::Global<v8::Value> global_result =
+        run_js_.Run(handle_request, context, parsed_v8_args.size(),
+                    parsed_v8_args.data());
+    if (try_catch.HasCaught()) {
+      try_catch.ReThrow();
+      return RequestResult::THROWN;
+    }
+    if (!global_result.IsEmpty())
+      *return_value = global_result.Get(isolate);
     return RequestResult::HANDLED;
   }