Fix multisample renderbuffer compliance (e.g. 3->4 samples) This change ensures that the following spec language is correctly implemented: the resulting value for RENDERBUFFER_SAMPLES is guaranteed to be greater than or equal to samples and no more than the next larger sample count supported by the implementation. For example, if 2, 4, and 8 samples are supported, and if 5 samples are requested, ANGLE should use 8 samples, and return 8 when GL_RENDERBUFFER_SAMPLES is queried. Note: There is a known problem with NVIDIA OpenGL driver that causes another test to be expected to fail. Bug: angleproject:2222 Bug: angleproject:4196 Change-Id: I28921badf9568427799b0af347198b5df06c2aaa Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1954444 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Ian Elliott <ianelliott@google.com>