Output the version of MSVS in chrome://version

chrome/browser/ui/webui/version_ui.cc

Index: chrome/browser/ui/webui/version_ui.cc
diff --git a/chrome/browser/ui/webui/version_ui.cc b/chrome/browser/ui/webui/version_ui.cc
index f9c70a1e20ca55507f8a401b2a9ddd9f10498f24..59e402a64bcedbeee292323bc3ad35f6e5ba0f3d 100644
--- a/chrome/browser/ui/webui/version_ui.cc
+++ b/chrome/browser/ui/webui/version_ui.cc
@@ -140,7 +140,13 @@ WebUIDataSource* CreateVersionUIDataSource() {
 #if defined(__clang__)
   html_source->AddString("compiler", "clang");
 #else
-  html_source->AddString("compiler", "MSVC");
+#if _MSC_VER == 1900

[Dan Beam, 2016/03/15 00:45:12]

can this #else + #if be #elif and one less #endif?

[Will Harris, 2016/03/15 01:23:30]

Done.

+  html_source->AddString("compiler", "MSVC 2015");
+#elif _MSC_VER == 1800
+  html_source->AddString("compiler", "MSVC 2013");
+#else
+#error "Unsupported version of MSVS compiler."
+#endif
 #endif
 #endif

[Dan Beam, 2016/03/15 00:45:12]

please add #endif  // defined(OS_WIN) to final #endif

[Dan Beam, 2016/03/15 00:45:12]

nit: is it possible to use mingw/g++ on windows?

https://groups.google.com/a/chromium.org/forum/#!topic/chromium-discuss/vagGh...
seems to imply "no"

if so:

#if defined(OS_WIN)
#if defined(__clang__)
  html_source->AddString("compiler", "clang");
#elif defined(_MSC_VER) && _MSC_VER == 1800
  html_source->AddString("compiler", "MSVC 2013");
#elif defined(_MSC_VER) && _MSC_VER == 1900
  html_source->AddString("compiler", "MSVC 2015");
#else
  html_source->AddString("compiler", "Unknown");
#endif
#endif  // defined(OS_WIN)

otherwise, lgtm

[Will Harris, 2016/03/15 01:23:30]

Done.

[Will Harris, 2016/03/15 01:23:30]

pretty sure you can't use g++ except maybe for base?

certainly not chrome code...

I'd like to still support Bruce's idea of erroring if we forget to update this
when we move to VS2018 so I'll leave the #error if it's MSVS but also support
the "Unknown" compiler if nothing else matches.