Steps to reproduce the problem:
1. Click 'Enable paint flashing', then trigger a progress bar（use transition to change width）on html page, see only the animation area twinkle;
2. Change Tab to 'Timeline' and enable 'paint' then start to record;
3. Click the paint bar where the progress bar worked, see the 'Paint Profile', it means that the whole page was repaint.
4. Up the progress bar to composite layer, repeat 3 step, then the paint area is only the progress bar.

What is the expected behavior?

What went wrong?
I know the reason why the whole page was repaint without up it to composite layer.But why step 1 show only the progress area repaint, not the whole page also?
ps: I attached files that named use the step;

Thank you very much!

Did this work before? N/A 

Chrome version: 51.0.2704.81  Channel: dev
OS Version: Android 6.0.1
Flash Version: Shockwave Flash 23.0 r0
 

Deleted: step1.png 17.3 KB

	step1.png 17.3 KB View Download

Deleted: step3.png 358 KB

	step3.png 358 KB View Download