[webkit-dev] ImageBitmap and OffscreenCanvas patches up for review

[zan at falconsigh.net]

Hi,

Igalians have  a couple of patches covering ImageBitmap and OffscreenCanvas functionality up for review, and would like to invite reviewers handy in this area to give them a look.

Here's initial ImageBitmap patches, covering creation from Blob objects and transfer support:
Implement createImageBitmap(Blob) -- https://bugs.webkit.org/show_bug.cgi?id=183247
Support transferring ImageBitmap objects -- https://bugs.webkit.org/show_bug.cgi?id=183131

There's further work necessary for complete ImageBitmap support that we want to undertake, as outlined in this meta bug:
https://bugs.webkit.org/show_bug.cgi?id=182424

And here's OffscreenCanvas patches, covering initial refactoring in CanvasBase and CanvasRenderingContext2DBase:
Move ImageBuffer-related functionality from HTMLCanvasElement to CanvasBase -- https://bugs.webkit.org/show_bug.cgi?id=182503
CanvasRenderingContext2DBase: use CanvasBase more extensively -- https://bugs.webkit.org/show_bug.cgi?id=182685

Similarly, we'll be taking on further work to get to a compliant OffscreenCanvas implementation:
https://bugs.webkit.org/show_bug.cgi?id=183720

Because all this functionality is based on platform abstractions like ImageBuffer and GraphicsContext, all the work is port-agnostic.

Reviews appreciated.

Regards,
Zan