Revert "Cleanup multiview support" This reverts commit 9a7c0b88ba68e328d3f5f7991a6df0ab5de92311. Reason for revert: Suspected cause of crash on Canary Original change's description: > Cleanup multiview support > > * Removed remaining mentions of ANGLE_multiview > > * Removed AST transformations used only in > the side-by-side multiview implementation > > * Changed the type of the internal ViewID_OVR > variable to use the dedicated qualifier > > * Removed side-by-side multiview support > from the D3D11 renderer > > * Removed an unused helper for side-by-side > multiview support from the OpenGL renderer > > * Removed obsoleted test suppressions > > Fixed: angleproject:3341 > Change-Id: I5e0706cbf26ea820b51400124ddbf2624b738f17 > Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4660046 > Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> > Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com> Bug: chromium:1462504 Bug: chromium:1462505 Bug: chromium:1462506 Bug: chromium:1462478 Bug: chromium:1462531 Change-Id: Ie0e76b1c6823db19f68bb67fdfc8abc00cc62f88 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4666209 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Auto-Submit: Shahbaz Youssefi <syoussefi@chromium.org> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com> Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>