Cache bound vertex and index buffers by ID3D11Buffer instead of serial. Since a DirectBuffer11 may return different buffers from getBuffer depending on the required buffer type and if the internal buffers are dirty or not, the current serial is not reliable. Use the actual buffer object so that there can be no missmatch. BUG=350581 Change-Id: I6ea1616273346117a17646edb68e6518e584f2b1 Reviewed-on: https://chromium-review.googlesource.com/189435 Reviewed-by: Shannon Woods <shannonwoods@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>