Roll src/third_party/perfetto ffa2b6de4a84..31b0a5681dea (1 commits)

https://android.googlesource.com/platform/external/perfetto.git/+log/ffa2b6de4a84..31b0a5681dea

git log ffa2b6de4a84..31b0a5681dea --date=short --first-parent --format='%ad %ae %s'
2019-11-29 rslawik@google.com Merge "Find system ion size during LMK"

Created with:
  gclient setdep -r src/third_party/perfetto@31b0a5681dea

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/perfetto-chromium-autoroll
Please CC perfetto-bugs@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

Bug: None
Tbr: perfetto-bugs@google.com
Change-Id: I1f6f350dd3d6bf0b548b22f03ba154c23d24e133
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1943381Reviewed-by: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Commit-Queue: chromium-autoroll <chromium-autoroll@skia-public.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#720168}

DEPS

@@ -1293,7 +1293,7 @@ deps = {
   },
 
   'src/third_party/perfetto':
-    Var('android_git') + '/platform/external/perfetto.git' + '@' + 'ffa2b6de4a845803757b3be1f7b127fb90e3337d',
+    Var('android_git') + '/platform/external/perfetto.git' + '@' + '31b0a5681deabef31e6a114fd954fc911f0c993f',
 
   'src/third_party/perl': {
       'url': Var('chromium_git') + '/chromium/deps/perl.git' + '@' + '6f3e5028eb65d0b4c5fdd792106ac4c84eee1eb3',