Enable depth buffer to workaround driver bug on Intel windows Rendering with depth buffer disabled and stencil buffer enabled leads to memory leak if we set viewport a large size on Intel windows platforms. So we enable depth buffer if stencil buffer is enabled to workaround this issue. TEST=gl_test.exe --gtest_filter=GLClearFramebufferTestWithParam/GLClearFramebufferTest.ClearDepthStencil/0 TEST=conformance/rendering/rendering-stencil-large-viewport.html TEST=RenderStencilBufferTest.DrawWithLargeViewport/ES3_D3D11 BUG=782317 Change-Id: Idb185db296f13e3fa897534514e198651a56439f Reviewed-on: https://chromium-review.googlesource.com/809574 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>