Fix narrowing of viz struct attribute.

The viz::RenderPassDrawQuad's render_pass_id is a RenderPassId which is
a uint64_t as is the mojom value. The struct trait although narrowed
it to an int32_t.

BUG=1082889

Change-Id: Ic2c851d40c46a7c5156209210285fb2961b1b20a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2210791Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770785}

services/viz/public/cpp/compositing/quads_mojom_traits.h

@@ -197,7 +197,7 @@ struct StructTraits<viz::mojom::DebugBorderQuadStateDataView, viz::DrawQuad> {
 
 template <>
 struct StructTraits<viz::mojom::RenderPassQuadStateDataView, viz::DrawQuad> {
-  static int32_t render_pass_id(const viz::DrawQuad& input) {
+  static uint64_t render_pass_id(const viz::DrawQuad& input) {
     const viz::RenderPassDrawQuad* quad =
         viz::RenderPassDrawQuad::MaterialCast(&input);
     DCHECK(quad->render_pass_id);