Simplify VersionInfo code, avoid hitting sandbox IPC constantly on Windows

chrome/browser/chromeos/drive/drive_integration_service.cc

Index: chrome/browser/chromeos/drive/drive_integration_service.cc
diff --git a/chrome/browser/chromeos/drive/drive_integration_service.cc b/chrome/browser/chromeos/drive/drive_integration_service.cc
index f0f771710d520c84c57ee687627ff3175b04b335..f786c9cc4ddbf112c493c1442bb46cf5209c28c4 100644
--- a/chrome/browser/chromeos/drive/drive_integration_service.cc
+++ b/chrome/browser/chromeos/drive/drive_integration_service.cc
@@ -78,9 +78,7 @@ std::string GetDriveUserAgent() {
   const char kDriveClientName[] = "chromedrive";
 
   chrome::VersionInfo version_info;
-  const std::string version = (version_info.is_valid() ?
-                               version_info.Version() :
-                               std::string("unknown"));
+  const std::string version = version_info.Version();
 
   // This part is <client_name>/<version>.
   const char kLibraryInfo[] = "chrome-cc/none";