Variations seed is pulled from the Java application on the first launch of Chrome

components/variations/service/variations_service_client.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_CLIENT_H_
 #define COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_CLIENT_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 41 matching lines @@
   // Gets the channel of the embedder.
   virtual version_info::Channel GetChannel() = 0;
 
   // Returns whether the embedder overrides the value of the restrict parameter.
   // |parameter| is an out-param that will contain the value of the restrict
   // parameter if true is returned.
   virtual bool OverridesRestrictParameter(std::string* parameter) = 0;
 
   // Called from VariationsService::PerformPreMainMessageLoopStartup().
   virtual void OnInitialStartup() {}
+
+#if defined(OS_ANDROID)
+  virtual base::Callback<void(std::string*, std::string*, std::string*)>
+      GetVariationsFirstRunSeedCallback() = 0;
+#endif  // OS_ANDROID
 };
 
 }  // namespace variations
 
 #endif  // COMPONENTS_VARIATIONS_SERVICE_VARIATIONS_SERVICE_CLIENT_H_