Roll Perfetto from 8fccd82e4e02 to 704a1aa4c802 (2 revisions)

https://android.googlesource.com/platform/external/perfetto.git/+log/8fccd82e4e02..704a1aa4c802

2021-01-13 treehugger-gerrit@google.com Merge "Migrate kTrackEventDescriptor to build time"
2021-01-13 hjd@google.com Merge "upkeep: Use empty() rather than size() == 0"

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/+doc/master/autoroll/README.md

Cq-Include-Trybots: luci.chromium.try:linux-perfetto-rel
Bug: None
Tbr: perfetto-bugs@google.com
Change-Id: I818943960691d5c413a9dc08ed1d3888c419577e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627061Reviewed-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@{#843033}

DEPS

@@ -1266,7 +1266,7 @@ deps = {
   },
 
   'src/third_party/perfetto':
-    Var('android_git') + '/platform/external/perfetto.git' + '@' + '8fccd82e4e02ac89d83739225d4118b59e8ba1cf',
+    Var('android_git') + '/platform/external/perfetto.git' + '@' + '704a1aa4c802df97a8203e052b77db2eabdb317a',
 
   'src/third_party/perl': {
       'url': Var('chromium_git') + '/chromium/deps/perl.git' + '@' + '6f3e5028eb65d0b4c5fdd792106ac4c84eee1eb3',