I have a customer currently in the process of porting Android to our i.MX6 platform and have noticed that the WebKit HTML5 performance is very poor. Similar performance is demonstrated on the SabreSD as well as custom HW, on both ICS and JB.
(Technically it is CSS3 transitions, not HTML5. The term HTML5 tends to encompass CSS3. )
If you go to a few simple HTML5 demos such as:
http://www.apple.com/html5/showcase/transitions/
http://www.juicebox.net/demos/pro/slider/
On i.MX6 the transitions are very jerky, and sometimes don't even happen. Is Android using the GPU for these transitions? It is evident that the opengl libraries are being loaded when a browser is opened but it is not clear if the HTML5 transitions specifically are using the GPU.
Examples have been tested on various phones and tablets running Android and smooth transitions are indicated. It is expected the performance of the i.MX6 to be comparable to the Android devices on the market today.
Please let me know if anyone hase any specific insigh as to the mechanism and optimization involved in these processes.