No, translateZ just makes it a composited layer. Hardware comes much later in the pipeline and possibly in another process.
The content of the layer isn't hardware rendered. It's rendered by the CPU and uploaded to a texture. In WebKit and probably Blink there's a fast path for images, canvas and video so that they can be directly uploaded or (on some platforms like Mac) bound to a texture avoiding an upload copy.
Microsoft and (maybe) Mozilla have a "hardware rendering" path via Direct2D, but Chrome and WebKit don't, they have compositors which can use the graphics hardware to perform compositing, but not rendering.
Core Animation layers have a mode in which Core Graphics calls targeting them are both processed asynchronously by a another thread and rasterized via OpenGL.
I presume you mean the "drawsAsynchronously" property. I'm extremely curious, does it really push the rasterization on the GPU? I mean, do you have shaders written, that do all the stuff that CPU normally does? Bezier paths, clipping, stroking, filling?
The content of the layer isn't hardware rendered. It's rendered by the CPU and uploaded to a texture. In WebKit and probably Blink there's a fast path for images, canvas and video so that they can be directly uploaded or (on some platforms like Mac) bound to a texture avoiding an upload copy.
Microsoft and (maybe) Mozilla have a "hardware rendering" path via Direct2D, but Chrome and WebKit don't, they have compositors which can use the graphics hardware to perform compositing, but not rendering.