Simplify VersionInfo code, avoid hitting sandbox IPC constantly on Windows

chrome/browser/chromeos/drive/drive_integration_service.cc

 // Copyright (c) 2012 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/chromeos/drive/drive_integration_service.h"
 
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "base/prefs/pref_service.h"
@@ skipping 60 matching lines @@
 // both WAPI and Drive API.  The user agent looks like:
 //
 // chromedrive-<VERSION> chrome-cc/none (<OS_CPU_INFO>)
 // chromedrive-24.0.1274.0 chrome-cc/none (CrOS x86_64 0.4.0)
 //
 // TODO(satorux): Move this function to somewhere else: crbug.com/151605
 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";
 
   const std::string os_cpu_info = content::BuildOSCpuInfo();
 
   // Add "gzip" to receive compressed data from the server.
   // (see https://developers.google.com/drive/performance)
   return base::StringPrintf("%s-%s %s (%s) (gzip)",
                             kDriveClientName,
@@ skipping 552 matching lines @@
         profile, preference_watcher,
         NULL, std::string(), base::FilePath(), NULL);
   } else {
     service = factory_for_test_->Run(profile);
   }
 
   return service;
 }
 
 }  // namespace drive