overlay: Fix Win viz_unittests Failure

For Windows overlay, we DCHECK that the output surface supports dc layer
overlay. In one of the GL Renderer unit tests for overlays, we didn't
set up the bool for support dc layer overlay and it was crashing on
bots.

R=rjkroege@chromium.org

Bug: 1022911
Change-Id: I0881615115e62c92e83e8239fc69631fb54c877e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1907202
Commit-Queue: weiliangc <weiliangc@chromium.org>
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714249}

components/viz/service/display/gl_renderer_unittest.cc

@@ -2265,6 +2265,9 @@ TEST_F(GLRendererTest, DontOverlayWithCopyRequests) {
   cc::FakeOutputSurfaceClient output_surface_client;
   std::unique_ptr<FakeOutputSurface> output_surface(
       FakeOutputSurface::Create3d());
+#if defined(OS_WIN)
+  output_surface->set_supports_dc_layers(true);
+#endif
   output_surface->BindToClient(&output_surface_client);
 
   std::unique_ptr<SharedBitmapManager> shared_bitmap_manager =