Convert //chrome/browser/extensions from scoped_ptr to std::unique_ptr

chrome/browser/extensions/extension_system_impl.cc

Index: chrome/browser/extensions/extension_system_impl.cc
diff --git a/chrome/browser/extensions/extension_system_impl.cc b/chrome/browser/extensions/extension_system_impl.cc
index 8e24a2b6bbd13d11137ee21abaa7fcc41dbae951..1a04022fd930d35a32b61799a4787d3f96cedf1a 100644
--- a/chrome/browser/extensions/extension_system_impl.cc
+++ b/chrome/browser/extensions/extension_system_impl.cc
@@ -395,7 +395,7 @@ ContentVerifier* ExtensionSystemImpl::content_verifier() {
   return shared_->content_verifier();
 }
 
-scoped_ptr<ExtensionSet> ExtensionSystemImpl::GetDependentExtensions(
+std::unique_ptr<ExtensionSet> ExtensionSystemImpl::GetDependentExtensions(
     const Extension* extension) {
   return extension_service()->shared_module_service()->GetDependentExtensions(
       extension);