ContextVk::handleNoopDrawEvent() was created to handle no-op
glDraw*'s. However, it assumed/assert'd a valid
mRenderPassCommandBuffer. That is not always the case.
Fix this by having handleDirtyEventLogImpl() check for a valid command
buffer.
Bug: b/189967673
Bug: b/184888395
Change-Id: Ice7c5da842a6f41f27c24af8e858147d01be86bc
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2935756Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Commit-Queue: Ian Elliott <ianelliott@google.com>
