Now Android 4.4 or higher device can use tool to record screen.
It's useful for developer who want to demo their apps.
1. Download the Android SDK
2. open the terminal
3. cd to the SDK path
4. start recording
./adb shell screenrecord /sdcard/demo.mp4
5. stop recording
Stop the screen recording by pressing Ctrl-C
6. Get the video
The video will be stored in you sd card.
Please reference the screenshot.