Use std::unique_ptr<base::Value> in V8ValueConverter.

content/renderer/dom_automation_controller.cc

Index: content/renderer/dom_automation_controller.cc
diff --git a/content/renderer/dom_automation_controller.cc b/content/renderer/dom_automation_controller.cc
index 3f119b6920d14f9590b722226bdfe2ea665f8bfc..91b456a383290f2769466a03d394b5a18415a9a3 100644
--- a/content/renderer/dom_automation_controller.cc
+++ b/content/renderer/dom_automation_controller.cc
@@ -102,8 +102,8 @@ bool DomAutomationController::SendMsg(const gin::Arguments& args) {
       (args.PeekNext()->IsString() || args.PeekNext()->IsBoolean() ||
        args.PeekNext()->IsNumber())) {
     V8ValueConverterImpl conv;
-    value.reset(
-        conv.FromV8Value(args.PeekNext(), args.isolate()->GetCurrentContext()));
+    value =
+        conv.FromV8Value(args.PeekNext(), args.isolate()->GetCurrentContext());
   } else {
     return false;
   }