trace_processor: implement span left join

Change-Id: Icc3de251453fe934920547606339b59eeab4bf85
diff --git a/test/trace_processor/index b/test/trace_processor/index
index 18af40a..ce26a86 100644
--- a/test/trace_processor/index
+++ b/test/trace_processor/index
@@ -57,6 +57,7 @@
 # Span join
 ../data/android_sched_and_ps.pb slice_span_join_b118665515.sql android_sched_and_ps_slice_span_join_b118665515.out
 synth_1.py span_join_unordered_cols.sql span_join_unordered_cols_synth_1.out
+../data/android_sched_and_ps.pb span_left_join.sql span_left_join.out
 
 # Window table
 ../data/android_sched_and_ps.pb smoke_window.sql android_sched_and_ps_smoke_window.out