Metal: Canvas resizing causes webpage to run out of memory For https://bugs.webkit.org/show_bug.cgi?id=232122 Introduce a maximum resident amount of memory that a single command buffer can use, before forcing a flush. As part of ensuring that a command buffer is ready, check to see if this limit is exceeded. if so, flush the command buffer, and create a new one. Bug: angleproject:6880 Change-Id: I5e89735d05adbc174237ab79b006a75bbe89e560 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3369922 Reviewed-by: Gregg Tavares <gman@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org> Commit-Queue: Kyle Piddington <kpiddington@apple.com>