#17143: merge with 3.3.

diff --cc Lib/trace.py
Simple merge

diff --cc Misc/NEWS
index f4ac978f0a1b677f7066108afc35450926dbedc1,ba2188637f8fbab975c774217f4e136375e94747..846c59f859195160ede529a7e4d0ce60c31750db
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -253,14 -178,11 +253,17 @@@ Core and Builtin
  Library
  -------
  
+ - Issue #17143: Fix a missing import in the trace module.  Initial patch by
+   Berker Peksag.
+ 
 +- Issue #15220: email.feedparser's line splitting algorithm is now simpler and
 +  faster.
 +
  - Issue #16743: Fix mmap overflow check on 32 bit Windows.
  
 +- Issue #16996: webbrowser module now uses shutil.which() to find a
 +  web-browser on the executable search path.
 +
  - Issue #16800: tempfile.gettempdir() no longer left temporary files when
    the disk is full.  Original patch by Amir Szekely.