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BUGS SHOULD BE FILED USING A DIFFERENT TEMPLATE!

Device name:
Android version:Android 5.1.1
WebView version (from system settings -> Apps -> Android System WebView):49.0.2623.105.0
Application:
webview sample apk with test.html
Application version:

URLs (if applicable):



Steps to reproduce:
(1)Launch any webview App with test.html.
(2)press Down2 button
(3)press Up2 button

Expected result:
App set transform and opacity animation time to 200 ms.
The animation should be smooth and within 200 ms.


Actual result:
There are two animations in order to do the navigation.
One is change opacity and one is transform.
And transform operation use % as unit.
Compositor doesn’t support transform if it depend on the box size.
So navigation animation is done by the blink.
And every frame from blink need a commit.
But v49 gets lot of raster tasks for every commit.
It cause the animation too slow.

Reason for laggy.
Because transform is done by the blink.
But the latency between the prepare tiles and DidFinishRunningTileTasks* tasks depends on 
how many tasks has been inserted into the task queue in the imply thread.
There are lot of tasks during the animation due to the compositor animation.
So there is a long pending tree:waiting during the animation duration.
It causes the transform laggy.

v41 webview doesn't have this issue.


 

Deleted: test.html 18.6 KB

test.html 18.6 KB View Download