[Extensions Bindings] Use gin::Arguments::GetAll()

extensions/renderer/declarative_event.cc

 // Copyright 2017 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/declarative_event.h"
 
 #include <algorithm>
 #include <memory>
 
 #include "base/memory/ptr_util.h"
@@ skipping 156 matching lines @@
   HandleFunction("events.Event.getRules", "events.getRules", arguments);
 }
 
 void DeclarativeEvent::HandleFunction(const std::string& signature_name,
                                       const std::string& request_name,
                                       gin::Arguments* arguments) {
   v8::Isolate* isolate = arguments->isolate();
   v8::HandleScope handle_scope(isolate);
   v8::Local<v8::Context> context = arguments->GetHolderCreationContext();
 
-  // TODO(devlin): This pattern is getting common. We should probably pull it
-  // out somewhere.
-  std::vector<v8::Local<v8::Value>> argument_list;
-  if (arguments->Length() > 0) {
-    // Just copying handles should never fail.
-    CHECK(arguments->GetRemaining(&argument_list));
-  }
+  std::vector<v8::Local<v8::Value>> argument_list = arguments->GetAll();
 
   // The events API has two undocumented parameters for each function: the name
   // of the event, and the "webViewInstanceId". Currently, stub 0 for webview
   // instance id.
   // TODO(devlin): We'll need to fix that to get it to work with webviews.
   // Longer term, it would be *great* to just factor that out entirely (can we
   // not get that information on the browser side? Investigate).
   argument_list.insert(argument_list.begin(),
                        {gin::StringToSymbol(isolate, event_name_),
                         v8::Integer::New(isolate, 0)});
@@ skipping 10 matching lines @@
     arguments->ThrowTypeError("Invalid invocation");
     return;
   }
 
   request_handler_->StartRequest(
       context, request_name, std::move(converted_arguments), callback,
       v8::Local<v8::Function>(), binding::RequestThread::UI);
 }
 
 }  // namespace extensions