Remove use of deprecated base::ListValue::Append(Value*) overload in extensions.

extensions/browser/app_window/app_window_contents.cc

Index: extensions/browser/app_window/app_window_contents.cc
diff --git a/extensions/browser/app_window/app_window_contents.cc b/extensions/browser/app_window/app_window_contents.cc
index 3cb0cb850de3f289aa460fa311a7ea026df77995..0d5f033c7efafc175859d61d1a7b754840c4caf1 100644
--- a/extensions/browser/app_window/app_window_contents.cc
+++ b/extensions/browser/app_window/app_window_contents.cc
@@ -4,6 +4,7 @@
 
 #include "extensions/browser/app_window/app_window_contents.h"
 
+#include <memory>
 #include <string>
 #include <utility>
 
@@ -65,9 +66,10 @@ void AppWindowContentsImpl::LoadContents(int32_t creator_process_id) {
 void AppWindowContentsImpl::NativeWindowChanged(
     NativeAppWindow* native_app_window) {
   base::ListValue args;
-  base::DictionaryValue* dictionary = new base::DictionaryValue();
-  args.Append(dictionary);
-  host_->GetSerializedState(dictionary);
+  std::unique_ptr<base::DictionaryValue> dictionary(
+      new base::DictionaryValue());
+  host_->GetSerializedState(dictionary.get());
+  args.Append(std::move(dictionary));
 
   content::RenderFrameHost* rfh = web_contents_->GetMainFrame();
   rfh->Send(new ExtensionMsg_MessageInvoke(