New Tool: MTStat

MTStat is a new tool to generate statistics on the gestures library.
It allows to replay large amounts of touchpad data and parses the
gestures library log output.
Each log statement starting with "MTStat:" will be counted and a
histogram of all lines will be calculated and displayed.
This tool processes about 1 hour of touchpad activity per second on a
Z620.
Remember to run $ make setup-in-place to get access to this tool.

BUG=chromium:248274
TEST=test this tool on the command line.

Change-Id: Ica44be7a806dd887a4163bf3c4e893a47b34fa30
Reviewed-on: https://gerrit.chromium.org/gerrit/59461
Reviewed-by: Dennis Kempin <denniskempin@chromium.org>
Tested-by: Dennis Kempin <denniskempin@chromium.org>
Commit-Queue: Dennis Kempin <denniskempin@chromium.org>
diff --git a/mtlib/platform.py b/mtlib/platform.py
index 7e66ff6..2ebabad 100644
--- a/mtlib/platform.py
+++ b/mtlib/platform.py
@@ -212,9 +212,9 @@
         if result:
           print ('multiple matching platforms:', result.name,
                  'and', platform.name)
-          sys.exit(-1)
+          return None
         result = platform
     if not result:
       print 'cannot find matching platform'
-      sys.exit(-1)
+      return None
     return result