update C++11 doc

site/dev/contrib/c++11.md

Index: site/dev/contrib/c++11.md
diff --git a/site/dev/contrib/c++11.md b/site/dev/contrib/c++11.md
index a8fc11dabfe56c9fe28c69baa6799900494e8d79..1854feb3b60b2c430c4e522d2a451e8f6393e521 100644
--- a/site/dev/contrib/c++11.md
+++ b/site/dev/contrib/c++11.md
@@ -10,9 +10,9 @@ feasibility.  This is about what we can use, a superset of what we may use.
 
 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 @@ internal Google projects.
 
 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 @@ Most of our bots are pretty up-to-date: the Windows bots use MSVC 2013, the Mac
 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.