Switch SupportsUserData uses to use unique_ptr.

gin/modules/module_registry.cc

Index: gin/modules/module_registry.cc
diff --git a/gin/modules/module_registry.cc b/gin/modules/module_registry.cc
index 3e8b47597601d035919bbc419cef4a2628979df4..99783d379202b461b46981547607a56404a52989 100644
--- a/gin/modules/module_registry.cc
+++ b/gin/modules/module_registry.cc
@@ -11,6 +11,7 @@
 #include <vector>
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "gin/arguments.h"
 #include "gin/converter.h"
 #include "gin/modules/module_registry_observer.h"
@@ -139,7 +140,7 @@ ModuleRegistry* ModuleRegistry::From(v8::Local<Context> context) {
     // PerContextData takes ownership of ModuleRegistryData.
     registry_data = new ModuleRegistryData;

[jsbell, 2017/04/27 17:00:11]

Just to avoid the unowned ptr here, an alternative:

ModuleRegistryData* data = static_cast<ModuleRegistryData*>(
    data->GetUserData(kModuleRegistryKey));
if (data)
  return registry_data->registry.get();

// PerContextData takes ownership of ModuleRegistryData.	 
unique_ptr<ModuleRegistryData> registry_data =
  base::MakeUnique<ModuleRegistryData>();
registry_data->registry.reset(
  new ModuleRegistry(context->GetIsolate()));
ModuleRegistry* registry = registry_data->registry.get();
data->SetUserData(kModuleRegistryKey, std::move(registry_data));
return registry;

... but that's probably harder to read, so whatever you prefer.

[Avi (use Gerrit), 2017/04/27 17:50:28]

This pattern is all over, so I'm not too worried.

     registry_data->registry.reset(new ModuleRegistry(context->GetIsolate()));
-    data->SetUserData(kModuleRegistryKey, registry_data);
+    data->SetUserData(kModuleRegistryKey, base::WrapUnique(registry_data));
   }
   return registry_data->registry.get();
 }