Roll src/third_party/perfetto 74bf49a9abc9..7a39c017c233 (3 commits)

https://android.googlesource.com/platform/external/perfetto.git/+log/74bf49a9abc9..7a39c017c233

git log 74bf49a9abc9..7a39c017c233 --date=short --no-merges --format='%ad %ae %s'
2019-08-15 primiano@google.com Merge "TraceProcessor: add clock-sync support at import time"
2019-08-15 khokhlov@google.com Merge "Trace processor: Parse legacy ftrace and legacy json trace events"
2019-08-15 taylori@google.com Merge "ui: Fix highlighting when selection is far to the left of screen"

Created with:
  gclient setdep -r src/third_party/perfetto@7a39c017c233

The AutoRoll server is located here: https://autoroll.skia.org/r/perfetto-chromium-autoroll

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

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


TBR=perfetto-bugs@google.com

Bug: None
Change-Id: I07374b39803d98a11d8ba2a507f23919dfa8b149
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1755981Reviewed-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@{#687331}

DEPS

@@ -1212,7 +1212,7 @@ deps = {
   },
 
   'src/third_party/perfetto':
-    Var('android_git') + '/platform/external/perfetto.git' + '@' + '74bf49a9abc9f0e82cb080cf315e03b69fe19a03',
+    Var('android_git') + '/platform/external/perfetto.git' + '@' + '7a39c017c23363ff74db70383b0d9d70fe748d42',
 
   'src/third_party/perl': {
       'url': Var('chromium_git') + '/chromium/deps/perl.git' + '@' + '6f3e5028eb65d0b4c5fdd792106ac4c84eee1eb3',