Avoid a crash when current version info is not obtainable.

chrome/installer/util/version.cc

 // Copyright (c) 2009 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 <vector>
 
 #include "base/format_macros.h"
 #include "base/string_util.h"
 #include "chrome/installer/util/version.h"
 
@@ skipping 20 matching lines @@
                                      && (build_ == other->build_)
                                      && (patch_ > other->patch_)));
 }
 
 installer::Version* installer::Version::GetVersionFromString(
     const string16& version_str) {
   std::vector<string16> numbers;
   SplitString(version_str, '.', &numbers);
 
   if (numbers.size() != 4) {
+    LOG(ERROR) << "Invalid version string: " << version_str;
     return NULL;
   }
 
   return new Version(StringToInt64(numbers[0]), StringToInt64(numbers[1]),
                      StringToInt64(numbers[2]), StringToInt64(numbers[3]));
 }