tools/valgrind/waterfall.sh: Only fetch the 3 most recent builds

tools/valgrind/waterfall.sh

 #!/bin/bash
 
 # Copyright (c) 2011 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.
 
 # This script can be used by waterfall sheriffs to fetch the status
 # of Valgrind bots on the memory waterfall and test if their local
 # suppressions match the reports on the waterfall.
 
@@ skipping 64 matching lines @@
     LIST_OF_BUILDS=$(cat "$LOGS_DIR/slave_$S" | \
                      awk 'BEGIN { buf = "" }
                           {
                             if ($0 ~ /<\/td>/) { buf = (buf $0); }
                             else {
                               if (buf) { print buf; buf="" }
                               print $0
                             }
                           }
                           END {if (buf) print buf}' | \
-                     grep "Failed" | \
+                     grep "success\|failure" | \
+                     head -n 3 | \
+                     grep "failure" | \
                      grep -v "failed compile" | \
                      sed "s/.*\/builds\///" | sed "s/\".*//")
 
     for BUILD in $LIST_OF_BUILDS
     do
       # We'll fetch a few tiny URLs now, let's use a temp file.
       TMPFILE=$(mktemp -t memory_waterfall.XXXXXX)
       download $SLAVE_URL/builds/$BUILD "$TMPFILE"
 
       REPORT_FILE="$LOGS_DIR/report_${S}_${BUILD}"
@@ skipping 68 matching lines @@
 elif [ "$1" = "blame" ]
 then
   echo The blame command died of bitrot. If you need it, please reimplement it.
   echo Reimplementation is blocked on http://crbug.com/82688
 else
   THISNAME=$(basename "${0}")
   echo "Usage: $THISNAME fetch|match"
   echo "  fetch - Fetch Valgrind logs from the memory waterfall"
   echo "  match - Test the local suppression files against the downloaded logs"
 fi