Vulkan: Flush pending suballoc garbage more often * Added a counter to the renderer object to keep track of the pending suballocation garbage. * mPendingSuballocationGarbageSizeInBytes * Once it surpasses a limit (mPendingSuballocationGarbageSizeLimit), it will flush the context so the pending garbages can be freed. * Currently the limit is based on the available heap sizes. It will use a fraction of the largest memory heap size. * The portion is currently kGarbageSizeLimitCoefficient = 0.2f. * At the end of the render pass, it is checked if the limit has been reached. If so, context flush will occur. Bug: b/280304441 Change-Id: I08e6028cfe20059ece2b2e4e971ece897544cd6d Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4787950 Reviewed-by: Charlie Lao <cclao@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Amirali Abdolrashidi <abdolrashidi@google.com>