Add the ancestor_slice dynamic table.

This table given a slice ID finds all parents by following the chain of
|parent_id| values.

This is useful to allow queries to quickly find the parent of the given
slice (imagine joining ancestor_slice(id) ON depth = 0).

Bug: 160148605
Change-Id: I4a60b03a2f3fb8d6d2741fcc5b4c2217d70eb3fe
diff --git a/Android.bp b/Android.bp
index a0f9563..eb51eaa 100644
--- a/Android.bp
+++ b/Android.bp
@@ -6712,6 +6712,7 @@
 filegroup {
   name: "perfetto_src_trace_processor_lib",
   srcs: [
+    "src/trace_processor/dynamic/ancestor_slice_generator.cc",
     "src/trace_processor/dynamic/describe_slice_generator.cc",
     "src/trace_processor/dynamic/experimental_counter_dur_generator.cc",
     "src/trace_processor/dynamic/experimental_flamegraph_generator.cc",