cc: Turn SharedQuadState into a struct-like class similar to DrawQuads.

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index e305b889cc546cabf4f99ad4753b3150560ced2f..a3f865611f7a0695c766c36ff4fb05958660af4f 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -466,10 +466,8 @@ bool LayerTreeHostImpl::calculateRenderPasses(FrameData& frame)
 
 #ifndef NDEBUG
     for (size_t i = 0; i < frame.renderPasses.size(); ++i) {
-        for (size_t j = 0; j < frame.renderPasses[i]->quadList().size(); ++j) {
+        for (size_t j = 0; j < frame.renderPasses[i]->quadList().size(); ++j)
             DCHECK(frame.renderPasses[i]->quadList()[j]->shared_quad_state);
-            DCHECK_GE(frame.renderPasses[i]->quadList()[j]->shared_quad_state->id, 0);
-        }
         DCHECK(frame.renderPassesById.contains(frame.renderPasses[i]->id()));
     }
 #endif