Add metrics for shader compilation time and shader blob size Log the time it takes for the system compiler to compile Metal and D3D shaders. Log the D3D shader blob size to get a sense of storage size needed. Bug: chromium:1481238 Change-Id: I300102dcb035f42e91d7819cd9465ff18436abf3 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4851196 Reviewed-by: Peng Huang <penghuang@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>