There are cases where we know that the next draw operation will fully
initialize a texture/renderbuffer and we can save the robust resource
init cost.

Default all resource init state to Initialized, any redefinition will
set it back to MayNeedInit.

After setting an individual texture image to initialized, check if
all images are now initialized and update the TextureState::mInitState
to match. The cost of this check is only performed after initializing
an image and allows future init checks to be faster.

Bug: chromium:1132514
Change-Id: Ia23664ae162559d1614f1eb5643e24a491d87f7f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2475456
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>