Moved the frame buffer specific logic from IOSGLContext to IOSGLRenderTarget.
use recording canvases for overlays
Support platform view overlays with gl rendering.
This also changes the overlay canvases (for both software and gl
rendering) be recording canvases, and only rasterize them after
finishing the paint traversal.
We are currently clearing the offscreen surface before rasterizing, but
as we draw the image snapshot of the offscreen surface into the onscreen
surface transparent pixels are blended with the current contents of the onscreen surface instead of replacing them. This is
particularly noticeable when embedding platform views.
For flow to manipulate the embedded UIViews during the paint traversal
it needs some hook in PaintContext.
This PR introduces a ViewEmbeder interface that is implemented by the
iOS PlatformViewsController and plumbs it into PaintContext.
The ViewEmbedder interface is mainly a place holder at this point, as
this PR is focused on just the plumbing.
This causes Skia to fall back to the ES2 shading language when the GL
driver doesn't clearly communicate that it supports the ES3 external
image extension. Doing so ensures that video playback (which relies on
external images) works on many more devices.
Michael Goderbauer
Jason Simmons
Amir Hardon
Mehmet Fidanboylu
Chinmay Garde
liyuqian
Brian Osman