Roll src/third_party/perfetto ab60e2ade15b..4629de24ad8b (2 commits)

https://android.googlesource.com/platform/external/perfetto.git/+log/ab60e2ade15b..4629de24ad8b

git log ab60e2ade15b..4629de24ad8b --date=short --first-parent --format='%ad %ae %s'
2019-12-05 primiano@google.com Delete CONTRIBUTING.md symlink
2019-12-05 primiano@google.com Merge "Improve docs"

Created with:
  gclient setdep -r src/third_party/perfetto@4629de24ad8b

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: Iece177bc51c5e8a5830647256e343ba509d267f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1952176Reviewed-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@{#721886}

DEPS

@@ -1297,7 +1297,7 @@ deps = {
   },
 
   'src/third_party/perfetto':
-    Var('android_git') + '/platform/external/perfetto.git' + '@' + 'ab60e2ade15b8df861bb6d0d4b5d577f49dbeb5b',
+    Var('android_git') + '/platform/external/perfetto.git' + '@' + '4629de24ad8b2c4ac3a0b211a4a3d5d79a67d0af',
 
   'src/third_party/perl': {
       'url': Var('chromium_git') + '/chromium/deps/perl.git' + '@' + '6f3e5028eb65d0b4c5fdd792106ac4c84eee1eb3',