Add histograms to compare GetVersionEx() with VerQueryValue() of kernel32

base/win/windows_version_unittest.cc

+// Copyright 2016 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 "base/win/windows_version.h"

[grt (UTC plus 2), 2016/03/11 16:13:42]

nit: blank line between this header and those below (the .h for the thing under
test always comes first and all by itself); see
https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes.

[scottmg, 2016/03/11 22:44:26]

Done.

+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace win {
+namespace {
+
+TEST(WindowsVersion, GetVersionExAndKernelVersionMatch) {
+  // If this fails, we're running in compatibility mode, or need to update the
+  // application manifest.
+  EXPECT_EQ(OSInfo::GetInstance()->version(),
+            OSInfo::GetInstance()->Kernel32Version());
+}
+
+}  // namespace
+}  // namespace win
+}  // namespace base