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

content/browser/browser_main_loop.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 "content/browser/browser_main_loop.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 113 matching lines @@
 #include "ui/ozone/public/client_native_pixmap_factory.h"
 #include "ui/ozone/public/ozone_platform.h"
 #endif
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <commctrl.h>
 #include <shellapi.h>
 
 #include "base/memory/memory_pressure_monitor_win.h"
+#include "base/win/windows_version.h"
 #include "content/common/sandbox_win.h"
 #include "net/base/winsock_init.h"
 #include "ui/base/l10n/l10n_util_win.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "base/memory/memory_pressure_monitor_chromeos.h"
 #include "chromeos/chromeos_switches.h"
 #endif
 
@@ skipping 1182 matching lines @@
                    CAUSE_FOR_GPU_LAUNCH_BROWSER_STARTUP));
   }
 
 #if defined(OS_MACOSX)
   ThemeHelperMac::GetInstance();
   SystemHotkeyHelperMac::GetInstance()->DeferredLoadSystemHotkeys();
 #endif  // defined(OS_MACOSX)
 
 #endif  // !defined(OS_IOS)
 
+#if defined(OS_WIN)
+  BrowserThread::PostDelayedTask(
+      BrowserThread::FILE, FROM_HERE,
+      base::Bind(&BrowserMainLoop::RecordWindowsVersionInformation),
+      base::TimeDelta::FromSeconds(3));
+#endif
+
   return result_code_;
 }
 
 bool BrowserMainLoop::UsingInProcessGpu() const {
   return parsed_command_line_.HasSwitch(switches::kSingleProcess) ||
          parsed_command_line_.HasSwitch(switches::kInProcessGPU);
 }
 
+#if defined(OS_WIN)
+void BrowserMainLoop::RecordWindowsVersionInformation() {

[ncarter (slow), 2016/03/10 18:19:27]

Does this instrumentation belong in content or chrome?

Did you consider putting this in chrome_browser_main_win.cc instead?

[ncarter (slow), 2016/03/10 18:21:40]

Also, perhaps chrome_browser_main_extra_parts_metrics.cc is an even better fit?

[scottmg, 2016/03/10 23:51:40]

Done.

+  UMA_HISTOGRAM_ENUMERATION("Windows.GetVersionExVersion",
+                            base::win::OSInfo::GetInstance()->version(),
+                            base::win::VERSION_WIN_LAST);

[grt (UTC plus 2), 2016/03/10 19:43:44]

please add a doc comment to enum Version in windows_version.h stating that it's
used for a histogram and values must not be reordered. while you're at it, add
an explicit " = N" value to each element so that this is crystal clear.

[scottmg, 2016/03/10 23:51:40]

Done.

+  UMA_HISTOGRAM_ENUMERATION("Windows.Kernel32Version",
+                            base::win::OSInfo::GetInstance()->Kernel32Version(),
+                            base::win::VERSION_WIN_LAST);
+  UMA_HISTOGRAM_BOOLEAN(
+      "Windows.InCompatibilityMode",
+      base::win::OSInfo::GetInstance()->version() !=
+          base::win::OSInfo::GetInstance()->Kernel32Version());
+}
+#endif  // OS_WIN
+
 bool BrowserMainLoop::InitializeToolkit() {
   TRACE_EVENT0("startup", "BrowserMainLoop::InitializeToolkit");
   TRACK_SCOPED_REGION("Startup", "BrowserMainLoop::InitializeToolkit");
 
   // TODO(evan): this function is rather subtle, due to the variety
   // of intersecting ifdefs we have.  To keep it easy to follow, there
   // are no #else branches on any #ifs.
   // TODO(stevenjb): Move platform specific code into platform specific Parts
   // (Need to add InitializeToolkit stage to BrowserParts).
   // See also GTK setup in EarlyInitialization, above, and associated comments.
@@ skipping 112 matching lines @@
   DCHECK(is_tracing_startup_for_duration_);
 
   is_tracing_startup_for_duration_ = false;
   TracingController::GetInstance()->StopTracing(
       TracingController::CreateFileSink(
           startup_trace_file_,
           base::Bind(OnStoppedStartupTracing, startup_trace_file_)));
 }
 
 }  // namespace content