[tools] Add script to convert telemetry json files for callstats.html

tools/callstats-from-telemetry.sh converts multiple telemetry results
form benchmark runs into a single callstats-compatible json file.

Change-Id: I775109d4274c2cf8d87797b73695497d82d59d4a
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2276043Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68630}

tools/callstats-from-telemetry.sh

+#1/bin/env bash
+set -e
+
+usage() {
+cat << EOF
+usage: $0 OPTIONS RESULTS_DIR
+
+Convert telemetry json trace result to callstats.html compatible
+versions ot ./out.json
+
+OPTIONS:
+  -h           Show this message.
+  RESULTS_DIR  tools/perf/artifacts/run_XXX
+EOF
+}
+
+
+while getopts ":h" OPTION ; do
+  case $OPTION in
+    h)  usage
+        exit 0
+        ;;
+    ?)  echo "Illegal option: -$OPTARG"
+        usage
+        exit 1
+        ;;
+  esac
+done
+
+# =======================================================================
+
+RESULTS_DIR=$1
+
+if [[ ! -e "$RESULTS_DIR" ]]; then
+  echo "RESULTS_DIR '$RESULTS_DIR' not found";
+  usage;
+  exit 1;
+fi
+
+
+OUT=out.json
+
+if [[ -e $OUT ]]; then
+  cp --backup=numbered $OUT $OUT.bak
+fi
+
+
+echo '{ "telemetry-results": { "placeholder":{}' > $OUT
+
+for PAGE_DIR in $RESULTS_DIR/*_1; do
+  PAGE=`basename $PAGE_DIR`;
+  JSON="$PAGE_DIR/trace/traceEvents/*_converted.json";
+  du -sh $JSON;
+  echo "Converting PAGE=$PAGE";
+  echo "," >> $OUT;
+  echo "\"$PAGE\": " >> $OUT;
+  jq '[.traceEvents[].args | select(."runtime-call-stats" != null) | ."runtime-call-stats"]' $JSON >> $OUT;
+done
+
+
+echo '}}' >> $OUT

tools/callstats.html

@@ -2148,8 +2148,28 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
   <div class="inline">
     <h2>Usage</h2>
     <ol>
-      <li>Install scipy, e.g. <code>sudo aptitude install python-scipy</code>
       <li>Build chrome.</li>
+    </ol>
+    <h3>Telemetry benchmark</h3>
+    <ol>
+      <li>Run <code>v8.browsing</code> benchmarks:
+        <pre>$CHROMIUM_DIR/tools/perf/run_benchmark run v8.browsing_desktop \
+          --browser=exact --browser-executable=$CHROMIUM_DIR/out/release/chrome \
+          --story-filter='.*2020 ' \
+          --also-run-disabled-tests
+        </pre>
+      </li>
+      <li>Install <a href="https://stedolan.github.io/jq/">jq</a>.</li>
+      <li>Convert the telemetry JSON files to callstats JSON file:
+        <pre>
+          $V8_DIR/tools/callstats-from-telemetry.sh $CHROMIUM_DIR/tools/perf/artifacts/run_XXXX
+        </pre>
+      </li>
+      <li>Load the generated <code>out.json</code></li>
+    </ol>
+    <h3>Raw approach</h3>
+    <ol>
+      <li>Install scipy, e.g. <code>sudo aptitude install python-scipy</code>
       <li>Check out a known working version of webpagereply:
         <pre>git -C $CHROME_DIR/third_party/webpagereplay checkout 7dbd94752d1cde5536ffc623a9e10a51721eff1d</pre>
       </li>