Have VariationsService get version for simulation callback from client

chrome/browser/metrics/variations/chrome_variations_service_client.cc

Index: chrome/browser/metrics/variations/chrome_variations_service_client.cc
diff --git a/chrome/browser/metrics/variations/chrome_variations_service_client.cc b/chrome/browser/metrics/variations/chrome_variations_service_client.cc
index 24577c839ba41411fb4e82563aa84a7586e1257e..93f383f5fbf81a1dffacdc4f8d6d38420f0ea49e 100644
--- a/chrome/browser/metrics/variations/chrome_variations_service_client.cc
+++ b/chrome/browser/metrics/variations/chrome_variations_service_client.cc
@@ -4,9 +4,34 @@
 
 #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() {}
@@ -19,6 +44,11 @@ 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();