Draw WebView in an offscreen GL buffer, then import and draw the
buffer with Vulkan.
Bug: 115610873
Test: Passed WebView CTS tests that are part of UiRendering.
Change-Id: Ida137fe9b8652d2a936ec2798b909be7e77b3462
Full GLES error checking layer via -include
trickery. Change DEBUG_OPENGL to a level system.
HIGH = every GL call is error checked
MODERATE = checkpointing at interesting spots
LOW = only asserts there are no errors at the end of a frame
or when the FBO changes
NONE = AIN'T GOT NO TIME FOR ERRORS GOTTA GO FAST!
Change-Id: Ibe81aae93d942059c4ddf1cbb11c828b7ce4c10b
