[tools/perf] Collect Chrome traces in power.mobile benchmark

This CL enables collecting Chrome events through perfetto system tracing
in the power.mobile benchmark.

Bug: 1151840
Change-Id: Iac07d6f9705d264867738e741ad743c7949f29a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2553426Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Mikhail Khokhlov <khokhlov@google.com>
Cr-Commit-Position: refs/heads/master@{#830528}

tools/perf/contrib/power_mobile/power_mobile.py

@@ -27,6 +27,8 @@ class PowerMobile(perf_benchmark.PerfBenchmark):
   def CreateCoreTimelineBasedMeasurementOptions(self):
     options = timeline_based_measurement.Options()
     options.config.enable_experimental_system_tracing = True
+    options.config.system_trace_config.EnableChrome(
+        chrome_trace_config=options.config.chrome_trace_config)
     options.config.system_trace_config.EnablePower()
     options.config.system_trace_config.EnableFtraceCpu()
     options.config.system_trace_config.EnableFtraceSched()