Add DCHECKs to match deserialization errors

Two checks about the DrawQuad rects were added as deserialization
errors. Add equivalent DCHECKs during serialization so the errors are
caught closer to the source in debug builds.

Bug: 1066139
Change-Id: I69665dd200d7ee2028fac6e55bd0264967ed9216
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134609Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: kylechar <kylechar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756252}

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

@@ -544,11 +544,13 @@ struct DrawQuadWithSharedQuadState {
 template <>
 struct StructTraits<viz::mojom::DrawQuadDataView, DrawQuadWithSharedQuadState> {
   static const gfx::Rect& rect(const DrawQuadWithSharedQuadState& input) {
+    DCHECK(input.quad->rect.size().GetCheckedArea().IsValid());
     return input.quad->rect;
   }
 
   static const gfx::Rect& visible_rect(
       const DrawQuadWithSharedQuadState& input) {
+    DCHECK(input.quad->rect.Contains(input.quad->visible_rect));
     return input.quad->visible_rect;
   }