D3D11: Resolve multisampled EGL surfaces at eglSwapBuffers Support for multisampled EGL surfaces was added in 151d5de (2017-04-13, "Enable MSAA for texture client buffers") but the resolve step was missing because it was not needed for EGL_ANGLE_d3d_texture_client_buffer. However, when using MSAA with a regular EGL surface then resolving is required to get an antialiased image. Please note that the new test case CreateSurfaceWithMSAA does actually not test the newly added resolve step because the resolve is performed by the glReadPixels() call there. So it is rather a general test if MSAA works for EGL surfaces. TEST=angle_end2end_tests.EGLSurfaceTest.CreateSurfaceWithMSAA Change-Id: Ieafd6877fa510d5e16c0d9c6872c31fa73efa86c Reviewed-on: https://chromium-review.googlesource.com/1181138 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Geoff Lang <geofflang@chromium.org>