update C++11 doc
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1678673002
NOTRY=true
DOCS_PREVIEW= https://skia.org/?cl=1678673002
Review URL: https://codereview.chromium.org/1678673002
diff --git a/site/dev/contrib/c++11.md b/site/dev/contrib/c++11.md
index a8fc11d..1854feb 100644
--- a/site/dev/contrib/c++11.md
+++ b/site/dev/contrib/c++11.md
@@ -10,9 +10,9 @@
The gist:
-- C++11 the language as supported by GCC 4.7 or later is probably usable.
+- C++11 the language as supported by GCC 4.7 or later is pretty usable.
+- The C++11 standard library can generally be used, with some teething.
- If you break a bot, that feature is not usable.
-- The C++11 standard library can't generally be used.
- Local statics are not thread safe.
@@ -24,27 +24,20 @@
Chrome builds with a recent Clang on Mac and Linux and with a recent MSVC on
Windows. These toolchains are new enough to not be the weak link to use any
-C++11 language feature. But Chrome still supports Mac OS X 10.6, which does
-not ship with a C++11 standard library. So [Chrome has banned the use of the
-C++11 standard library](http://chromium-cpp.appspot.com/). Some header-only
-features are probably technically fine, but the Mac toolchain will prevent us
-from even trying at compile time as long as we target 10.6 as our minimum API
-level.
+C++11 language feature.
Chrome intentionally disables thread-safe initialization of static variables,
-and MSVC doesn't support it at all, so we cannot rely on that.
+so we cannot rely on that. Our bots disable this too, so keep an eye on TSAN.
-Android builds with either a recent GCC or a recent Clang. They're generally
-not a weak link for C++11 language features. Android's C++ standard library
-has always been a pain, but since we can't use it anyway (see Chrome), don't
-worry about it.
+Android builds with either a somewhat aged GCC or a recent Clang. They're
+generally not a weak link for C++11 language features. Android's C++ standard
+library had historically been a pain, but seems to work fine these days.
Mozilla's current weak link is a minimum requirement of GCC 4.7. Most features
marked in red on Mozilla's C++11 [feature
matrix](https://developer.mozilla.org/en-US/docs/Using_CXX_in_Mozilla_code) are
marked that way because they arrived in GCC 4.8. Their minimum-supported Clang
-and MSVC toolchains are great. They also appear to ban the C++ standard
-library.
+and MSVC toolchains are pretty good, but MSVC 2013 will become the weak link soon.
Internal Google projects tend to support C++11 completely, including the
full C++11 standard library.
@@ -57,6 +50,6 @@
bots a recent Clang, and the Linux bots GCC 4.8 or a recent Clang. Our Android
bots use a recent toolchain from Android (see above), and our Chrome bots use
Chrome's toolchains (see above). I'm not exactly sure what our Chrome OS bots
-are using, but they've never been a problem.
+are using. They're probably our weak link right now, though problems are rare.
I believe our bots' ability to use C++11 matches Mozilla's list nearly identically.