Have VariationsService get version for simulation callback from client

chrome/browser/metrics/variations/chrome_variations_service_client.cc

 // 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.
 
 #include "chrome/browser/metrics/variations/chrome_variations_service_client.h"
 
+#include "base/bind.h"
 #include "chrome/browser/browser_process.h"
+#include "components/version_info/version_info.h"
 #include "content/public/browser/browser_thread.h"
 
+#if !defined(OS_ANDROID) && !defined(OS_IOS) && !defined(OS_CHROMEOS)
+#include "chrome/browser/upgrade_detector_impl.h"
+#endif
+
+namespace {
+
+// Gets the version number to use for variations seed simulation. Must be called
+// on a thread where IO is allowed.
+base::Version GetVersionForSimulation() {
+#if !defined(OS_ANDROID) && !defined(OS_IOS) && !defined(OS_CHROMEOS)
+  const base::Version installed_version =
+      UpgradeDetectorImpl::GetCurrentlyInstalledVersion();
+  if (installed_version.IsValid())
+    return installed_version;
+#endif  // !defined(OS_ANDROID) && !defined(OS_IOS) && !defined(OS_CHROMEOS)
+
+  // TODO(asvitkine): Get the version that will be used on restart instead of
+  // the current version on Android, iOS and ChromeOS.
+  return base::Version(version_info::GetVersionNumber());
+}
+
+}  // namespace
+
 ChromeVariationsServiceClient::ChromeVariationsServiceClient() {}
 
 ChromeVariationsServiceClient::~ChromeVariationsServiceClient() {}
 
 std::string ChromeVariationsServiceClient::GetApplicationLocale() {
   return g_browser_process->GetApplicationLocale();
 }
 
 base::SequencedWorkerPool* ChromeVariationsServiceClient::GetBlockingPool() {
   return content::BrowserThread::GetBlockingPool();
 }
 
+base::Callback<base::Version(void)>
+ChromeVariationsServiceClient::GetVersionForSimulationCallback() {
+  return base::Bind(&GetVersionForSimulation);
+}
+
 net::URLRequestContextGetter*
 ChromeVariationsServiceClient::GetURLRequestContext() {
   return g_browser_process->system_request_context();
 }
 
 network_time::NetworkTimeTracker*
 ChromeVariationsServiceClient::GetNetworkTimeTracker() {
   return g_browser_process->network_time_tracker();
 }
 
 void ChromeVariationsServiceClient::OnInitialStartup() {
 #if defined(OS_WIN)
   StartGoogleUpdateRegistrySync();
 #endif
 }
 
 #if defined(OS_WIN)
 void ChromeVariationsServiceClient::StartGoogleUpdateRegistrySync() {
   registry_syncer_.RequestRegistrySync();
 }
 #endif