Handle nullptr in GetQueryObjectParameter() There are applications that disable validation using EGL_CONTEXT_OPENGL_NO_ERROR_KHR extension. In such usecases the GetQueryObjectParameter() method needs to account for the possibility that the query object has not yet been created. Bug: angleproject:5704 Tests: angle_end2end_tests --gtest_filter=QueryObjectTest* Change-Id: Ib9e1cb32a6d64f2772124178223cf07cbb84691b Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2729298 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Mohan Maiya <m.maiya@samsung.com>