For rendering yes. For video decoding no. Chromium needs a patch to use VA-API[1].

[1]: https://wiki.archlinux.org/index.php/Chromium#Hardware_video...

Seems to be. From about:gpu:

    Graphics Feature Status
    Canvas: Hardware accelerated
    Flash: Hardware accelerated
    Flash Stage3D: Hardware accelerated
    Flash Stage3D Baseline profile: Hardware accelerated
    Compositing: Hardware accelerated
    Multiple Raster Threads: Enabled
    Native GpuMemoryBuffers: Software only. Hardware acceleration disabled
    Out-of-process Rasterization: Disabled
    Hardware Protected Video Decode: Hardware accelerated
    Rasterization: Software only. Hardware acceleration disabled
    Skia Deferred Display List: Disabled
    Skia Renderer: Disabled
    Surface Control: Disabled
    Surface Synchronization: Enabled
    Video Decode: Hardware accelerated
    Viz Service Display Compositor: Disabled
    WebGL: Hardware accelerated
    WebGL2: Hardware accelerated