[Extensions Bindings] Allow for argument validation without conversion

extensions/renderer/api_bindings_system_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/renderer/api_bindings_system.h"
 
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
@@ skipping 281 matching lines @@
   }
 }
 
 // Tests adding a custom hook to an API.
 TEST_F(APIBindingsSystemTest, TestCustomHooks) {
   v8::HandleScope handle_scope(isolate());
   v8::Local<v8::Context> context = ContextLocal();
 
   bool did_call = false;
   auto hook = [](bool* did_call, const APISignature* signature,
-                 gin::Arguments* arguments) {
+                 gin::Arguments* arguments,
+                 const ArgumentSpec::RefMap& type_refs) {
     *did_call = true;
     std::string argument;
     EXPECT_EQ(2, arguments->Length());
     EXPECT_TRUE(arguments->GetNext(&argument));
     EXPECT_EQ("foo", argument);
     v8::Local<v8::Function> function;
-    ASSERT_TRUE(arguments->GetNext(&function));
+    EXPECT_TRUE(arguments->GetNext(&function));
+    // The above EXPECT_TRUE should really be an ASSERT, but that messes with
+    // the return type.
+    if (function.IsEmpty())
+      return APIBindingHooks::RequestResult::HANDLED;
     v8::Local<v8::String> response =
         gin::StringToV8(arguments->isolate(), "bar");
     v8::Local<v8::Value> response_args[] = {response};
     RunFunctionOnGlobal(function, arguments->isolate()->GetCurrentContext(),
                         1, response_args);
+    return APIBindingHooks::RequestResult::HANDLED;
   };
 
   APIBindingHooks* hooks = bindings_system()->GetHooksForAPI(kAlphaAPIName);
   ASSERT_TRUE(hooks);
   hooks->RegisterHandleRequest(
       "alpha.functionWithCallback",
       base::Bind(hook, &did_call));
 
   v8::Local<v8::Object> alpha_api = bindings_system()->CreateAPIInstance(
       kAlphaAPIName, context, isolate(), base::Bind(&AllowAllAPIs), nullptr);
@@ skipping 161 matching lines @@
                                           *ListValueFromString("['active']"));
 
     std::unique_ptr<base::Value> result =
         GetBaseValuePropertyFromObject(context->Global(), context, "idleState");
     ASSERT_TRUE(result);
     EXPECT_EQ("\"active\"", ValueToString(*result));
   }
 }
 
 }  // namespace extensions