Add Startup.BrowserView.FirstPaint / .CompositingEnded histograms.

chrome/browser/metrics/startup_metrics_browsertest.cc

+// Copyright 2017 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.
+
+#include <set>
+
+#include "base/metrics/histogram_samples.h"
+#include "base/metrics/statistics_recorder.h"
+#include "base/run_loop.h"
+#include "chrome/test/base/in_process_browser_test.h"
+
+using StartupMetricsTest = InProcessBrowserTest;
+
+namespace {
+
+constexpr const char* kStartupMetrics[] = {
+    "Startup.BrowserMainToRendererMain",
+    "Startup.BrowserOpenTabs",
+    "Startup.BrowserWindow.FirstPaint",
+    "Startup.BrowserWindow.FirstPaint.CompositingEnded",
+    "Startup.BrowserWindowDisplay",
+    "Startup.FirstWebContents.MainFrameLoad2",
+    "Startup.FirstWebContents.MainNavigationFinished",
+    "Startup.FirstWebContents.MainNavigationStart",
+    "Startup.FirstWebContents.NonEmptyPaint2",
+
+    // The following histograms depend on normal browser startup through
+    // BrowserMain and are as such not caught by this browser test.
+    // "Startup.BrowserMessageLoopStartHardFaultCount",
+    // "Startup.BrowserMessageLoopStartTime",
+    // "Startup.BrowserMessageLoopStartTimeFromMainEntry2",
+    // "Startup.LoadTime.ExeMainToDllMain2",
+    // "Startup.LoadTime.ProcessCreateToDllMain2",
+    // "Startup.LoadTime.ProcessCreateToExeMain2",
+    // "Startup.SystemUptime",
+    // "Startup.Temperature",
+};
+
+}  // namespace
+
+// Verify that startup histograms are logged on browser startup.
+IN_PROC_BROWSER_TEST_F(StartupMetricsTest, ReportsValues) {
+  for (auto* const histogram : kStartupMetrics) {
+    while (!base::StatisticsRecorder::FindHistogram(histogram))
+      base::RunLoop().RunUntilIdle();
+  }
+}