cc: Fix negative integer overflow in RenderPass serialization code.

cc/ipc/render_pass_struct_traits.cc

Index: cc/ipc/render_pass_struct_traits.cc
diff --git a/cc/ipc/render_pass_struct_traits.cc b/cc/ipc/render_pass_struct_traits.cc
index 86797298da516a899b4f5e182193c81a60e615dc..429ce05ca2118e003d7af12168326eb3ac4fa77f 100644
--- a/cc/ipc/render_pass_struct_traits.cc
+++ b/cc/ipc/render_pass_struct_traits.cc
@@ -71,7 +71,8 @@ bool StructTraits<cc::mojom::RenderPass, std::unique_ptr<cc::RenderPass>>::Read(
     if (!(*it)->shared_quad_state)
       return false;
   }
-  return sqs_iter.index() == (*out)->shared_quad_state_list.size() - 1;
+  return (*out)->shared_quad_state_list.empty() ||
+         sqs_iter.index() == (*out)->shared_quad_state_list.size() - 1;
 }
 
 }  // namespace mojo