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

base/win/windows_version.h

 // 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.
 
 #ifndef BASE_WIN_WINDOWS_VERSION_H_
 #define BASE_WIN_WINDOWS_VERSION_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 68 matching lines @@
   // the process does not have sufficient access rights to determine this.
   enum WOW64Status {
     WOW64_DISABLED,
     WOW64_ENABLED,
     WOW64_UNKNOWN,
   };
 
   static OSInfo* GetInstance();
 
   Version version() const { return version_; }
+  Version kernel32_version() const { return kernel32_version_; }

[Will Harris, 2016/03/09 23:02:50]

how are none of these functions commented...? :)

[scottmg, 2016/03/10 00:41:31]

Doesn't seem like comments would be very useful.

   // The next two functions return arrays of values, [major, minor(, build)].
   VersionNumber version_number() const { return version_number_; }
   VersionType version_type() const { return version_type_; }
   ServicePack service_pack() const { return service_pack_; }
   WindowsArchitecture architecture() const { return architecture_; }
   int processors() const { return processors_; }
   size_t allocation_granularity() const { return allocation_granularity_; }
   WOW64Status wow64_status() const { return wow64_status_; }
   std::string processor_model_name();
 
   // Like wow64_status(), but for the supplied handle instead of the current
   // process.  This doesn't touch member state, so you can bypass the singleton.
   static WOW64Status GetWOW64StatusForProcess(HANDLE process_handle);
 
  private:
   OSInfo();
   ~OSInfo();
 
   Version version_;
+  Version kernel32_version_;
   VersionNumber version_number_;
   VersionType version_type_;
   ServicePack service_pack_;
   WindowsArchitecture architecture_;
   int processors_;
   size_t allocation_granularity_;
   WOW64Status wow64_status_;
   std::string processor_model_name_;
 
   DISALLOW_COPY_AND_ASSIGN(OSInfo);
 };
 
 // Because this is by far the most commonly-requested value from the above
 // singleton, we add a global-scope accessor here as syntactic sugar.
 BASE_EXPORT Version GetVersion();
 
 }  // namespace win
 }  // namespace base
 
 #endif  // BASE_WIN_WINDOWS_VERSION_H_