Fix highlighting in async daily report.

Deltas in the number of tests run should be highlighted. The initial
async-report implementation forgot to do that, so this commit adds it!

Change-Id: I64c3a6958f33b31d242180249316bc67da39e60b

Author: georges-arm

lnt/server/ui/templates/reporting/daily_report_async.html

@@ -371,11 +371,14 @@ <h3>Result Table ({{ field.display_name }})</h3>
         rmo_elem.innerHTML = '<a href="{{ ts_url }}/' + key_run.id + '">' + key_run.llvm_project_revision + '</a>'
       }
     }
+    const nr_tests_for_machine = res.data.nr_tests_table['' + machine.id];
     for (var i=0; i<{{ report.num_prior_days_to_include }}; i++) {
       const nots_td_id = "nots-" + machine.id + "-" + i;
-      const nots_val = res.data.nr_tests_table['' + machine.id][i];
+      const nots_val = nr_tests_for_machine[i];
       const nots_elem = document.getElementById(nots_td_id);
-      nots_elem.style.backgroundColor = "";
+      if (nr_tests_for_machine[i + 1] === undefined || nr_tests_for_machine[i + 1] == nots_val) {
+        nots_elem.style.backgroundColor = "";
+      }
       nots_elem.innerHTML = '' + nots_val;
     }
     var today_key_run = res.data.machine_runs['' + machine.id]["0"];