The Systrace tool helps analyze the performance of your game by capturing and displaying execution times of your game processes and other Android system processes. The tool combines data from the Android kernel such as the CPU scheduler, disk activity, and application threads to generate an HTML report that shows an overall picture of an Android device’s system processes for a given period of time.
In addition to system event monitoring, Systrace provides a Native Tracing API for custom event tracing. This API is incredibly useful for drilling down into game engine performance to understand exactly where CPU time is being spent.
You can learn more about the tool on Google's Systrace overview page.
Systrace Command Line User Guide
Systrace - Native Tracing