[Content] Update V8ValueConverter::create to return a std::unique_ptr

extensions/renderer/event_bindings.cc

 // Copyright 2014 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/event_bindings.h"
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
@@ skipping 258 matching lines @@
   CHECK_EQ(2, args.Length());
   CHECK(args[0]->IsString());
   CHECK(args[1]->IsObject());
 
   std::string event_name = *v8::String::Utf8Value(args[0]);
   if (!context()->HasAccessOrThrowError(event_name))
     return;
 
   std::unique_ptr<base::DictionaryValue> filter;
   {
-    std::unique_ptr<content::V8ValueConverter> converter(
-        content::V8ValueConverter::create());
-    std::unique_ptr<base::Value> filter_value(converter->FromV8Value(
-        v8::Local<v8::Object>::Cast(args[1]), context()->v8_context()));
+    std::unique_ptr<base::Value> filter_value =
+        content::V8ValueConverter::Create()->FromV8Value(
+            v8::Local<v8::Object>::Cast(args[1]), context()->v8_context());
     if (!filter_value || !filter_value->IsType(base::Value::Type::DICTIONARY)) {
       args.GetReturnValue().Set(static_cast<int32_t>(-1));
       return;
     }
     filter = base::DictionaryValue::From(std::move(filter_value));
   }
 
   int id = g_event_filter.Get().AddEventMatcher(
       event_name, ParseEventMatcher(std::move(filter)));
   if (id == -1) {
@@ skipping 96 matching lines @@
   // Same for filtered events.
   std::set<int> attached_matcher_ids_safe = attached_matcher_ids_;
   for (int matcher_id : attached_matcher_ids_safe) {
     DetachFilteredEvent(matcher_id, false /* is_manual */);
   }
   DCHECK(attached_matcher_ids_.empty())
       << "Filtered events cannot be attached during invalidation";
 }
 
 }  // namespace extensions