Vulkan: Remove ContextVk::retainResource and retainImage() Clean up some retain* APIs. retainImge and retainReadOnlyResource and retainResource are doing exact same thing, they are consolidated into just retainResource. ContextVk::retainResource is removed since mUse can now safely copied from DescriptorSetHelperPool object which tracks mUse. Bug: b/262047600 Change-Id: I56ea08696e870826bd94ccb79dd621f35923bc6a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4114500 Reviewed-by: Yuxin Hu <yuxinhu@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Charlie Lao <cclao@google.com>