telemetry: Add SimulateMemoryPressureNotification() to ActionRunner
telemetry: Add SimulateMemoryPressureNotification() to ActionRunner

We already implemented it in Browser. Expose it to ActionRunner so that
a page_set can invoke it. BlinkMemoryMobilePageSet uses it.

BUG=519146

Review URL: https://codereview.chromium.org/1492733002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#363751}

catapult-project/catapult-csm,sahiljain/catapult,benschmaus/catapult,catapult-project/catapult,benschmaus/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,catapult-project/catapult-csm,catapult-project/catapult-csm,sahiljain/catapult,catapult-project/catapult-csm,catapult-project/catapult,sahiljain/catapult,sahiljain/catapult,SummerLW/Perf-Insight-Report,benschmaus/catapult,sahiljain/catapult,benschmaus/catapult,catapult-project/catapult-csm,SummerLW/Perf-Insight-Report,benschmaus/catapult,benschmaus/catapult,SummerLW/Perf-Insight-Report,catapult-project/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,catapult-project/catapult,sahiljain/catapult,catapult-project/catapult,benschmaus/catapult,catapult-project/catapult