Add TimeDelta support to PerfResultReporter

Adds support for base::TimeDelta in PerfResultReporter. This is due to
many perf tests reporting time taken from a TimeDelta, and handling the
conversion from TimeDelta to double in PerfResultReporter makes its use
less error-prone since users no longer need to worry about matching the
registered units to the correct TimeDelta::In*seconds calls.

Bug: 923564
Change-Id: I30dd6bcf0f11489b671f20e6e776fbad4659729e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1815081Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Auto-Submit: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702153}

chrome/browser/vr/text_perftest.cc

@@ -52,8 +52,7 @@ class TextPerfTest : public testing::Test {
   }
 
   void PrintResults() {
-    reporter_->AddResult(".render_time_avg",
-                         timer_.TimePerLap().InMillisecondsF());
+    reporter_->AddResult(".render_time_avg", timer_.TimePerLap());
     reporter_->AddResult(".number_of_runs",
                          static_cast<size_t>(timer_.NumLaps()));
   }

testing/perf/perf_result_reporter.cc

@@ -52,6 +52,34 @@ void PerfResultReporter::AddResult(const std::string& metric_suffix,
               iter->second.units, iter->second.important);
 }
 
+void PerfResultReporter::AddResult(const std::string& metric_suffix,
+                                   const base::TimeDelta& value) {
+  auto iter = metric_map_.find(metric_suffix);
+  CHECK(iter != metric_map_.end());
+
+  // Decide what time unit to convert the TimeDelta into. Units are based on
+  // the legacy units in
+  // https://cs.chromium.org/chromium/src/third_party/catapult/tracing/tracing/value/legacy_unit_info.py?q=legacy_unit_info
+  double time = 0;
+  if (iter->second.units == "seconds") {
+    time = value.InSecondsF();
+  } else if (iter->second.units == "ms" ||
+             iter->second.units == "milliseconds") {
+    time = value.InMillisecondsF();
+  } else if (iter->second.units == "us") {
+    time = value.InMicrosecondsF();
+  } else if (iter->second.units == "ns") {
+    time = value.InNanoseconds();
+  } else {
+    NOTREACHED() << "Attempted to use AddResult with a TimeDelta when "
+                 << "registered unit for metric " << metric_suffix << " is "
+                 << iter->second.units;
+  }
+
+  PrintResult(metric_basename_, metric_suffix, story_name_, time,
+              iter->second.units, iter->second.important);
+}
+
 void PerfResultReporter::AddResultList(const std::string& metric_suffix,
                                        const std::string& values) {
   auto iter = metric_map_.find(metric_suffix);

testing/perf/perf_result_reporter.h

@@ -8,6 +8,8 @@
 #include <string>
 #include <unordered_map>
 
+#include "base/time/time.h"
+
 namespace perf_test {
 
 struct MetricInfo {
@@ -45,6 +47,11 @@ class PerfResultReporter {
   void AddResult(const std::string& metric_suffix, size_t value);
   void AddResult(const std::string& metric_suffix, double value);
   void AddResult(const std::string& metric_suffix, const std::string& value);
+  // A special version of AddResult that will automatically convert the given
+  // TimeDelta into a double with the correct units for the registered metric.
+  void AddResult(const std::string& metric_suffix,
+                 const base::TimeDelta& value);
+
   void AddResultList(const std::string& metric_suffix,
                      const std::string& values);