Reject CompositorFrames with no render passes when deserializing

cc/ipc/compositor_frame_struct_traits.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/ipc/compositor_frame_struct_traits.h"
 #include "cc/ipc/compositor_frame_metadata_struct_traits.h"
 #include "cc/ipc/render_pass_struct_traits.h"
 #include "cc/ipc/transferable_resource_struct_traits.h"
 
 namespace mojo {
 
 // static
 bool StructTraits<cc::mojom::CompositorFrameDataView,
                   cc::CompositorFrame>::Read(cc::mojom::CompositorFrameDataView
                                                  data,
                                              cc::CompositorFrame* out) {
-  if (!data.ReadMetadata(&out->metadata))
-    return false;
-
-  return data.ReadResources(&out->resource_list) &&
-         data.ReadPasses(&out->render_pass_list);
+  return data.ReadPasses(&out->render_pass_list) &&
+         !out->render_pass_list.empty() && data.ReadMetadata(&out->metadata) &&
+         data.ReadResources(&out->resource_list);
 }
 
 }  // namespace mojo