Revert "Reland "iOS: Save perf results under Documents/perf_result.json""

This reverts commit 8b886bb077d54e2bf6198559557ae97b03023611.

Reason for revert: Breaks downstream projects.

Original change's description:
> Reland "iOS: Save perf results under Documents/perf_result.json"
> 
> This will require a manual roll to downstream projects, since
> the //test:perf_test target was introduced.
> 
> This is a reland of 10a8e7a9b5261a7e3ce19900ba3511be3b5911f8
> Original change's description:
> > iOS: Save perf results under Documents/perf_result.json
> >
> > TBR=henrika@webrtc.org
> >
> > Bug: webrtc:7156
> > Change-Id: Ib00992cce0007e0b5c9274340df1a892f810b0c5
> > Reviewed-on: https://webrtc-review.googlesource.com/29202
> > Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
> > Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
> > Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
> > Cr-Commit-Position: refs/heads/master@{#21244}
> 
> TBR=henrika@webrtc.org, phoglund@webrtc.org
> 
> No-Try: true
> Bug: webrtc:7156
> Change-Id: Iecdb108f605fd1c98acde4d50ab4f5a7b5f6bfaf
> Reviewed-on: https://webrtc-review.googlesource.com/32761
> Reviewed-by: Edward Lemur <ehmaldonado@webrtc.org>
> Commit-Queue: Edward Lemur <ehmaldonado@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#21252}

TBR=phoglund@webrtc.org,ehmaldonado@webrtc.org,henrika@webrtc.org

Change-Id: If4c72fa61dba3a3157fb9696b7f22664522b9467
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:7156
Reviewed-on: https://webrtc-review.googlesource.com/33040
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21279}

rtc_base/unittest_main.cc

@@ -109,7 +109,7 @@ int main(int argc, char* argv[]) {
   rtc::SSLStreamAdapter::enable_time_callback_for_testing();
 
 #if defined(WEBRTC_IOS)
-  rtc::test::InitTestSuite(RUN_ALL_TESTS, argc, argv, false);
+  rtc::test::InitTestSuite(RUN_ALL_TESTS, argc, argv);
   rtc::test::RunTestsFromIOSApp();
 #endif
   const int res = RUN_ALL_TESTS();