Require a PrefService in startup_metric_utils::RecordBrowserMainMessageLoopStart

components/startup_metric_utils/browser/startup_metric_utils.cc

 // Copyright 2013 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 "components/startup_metric_utils/browser/startup_metric_utils.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 168 matching lines @@
     return;
 
   UMA_HISTOGRAM_WITH_STARTUP_TEMPERATURE(UMA_HISTOGRAM_LONG_TIMES_100,
                                          "Startup.SystemUptime",
                                          GetSystemUptimeOnProcessLaunch());
 }
 
 // On Windows, records the number of hard-faults that have occurred in the
 // current chrome.exe process since it was started. A version of the histograms
 // recorded in this method suffixed by |same_version_startup_count| will also be
-// recorded (unless |same_version_startup_count| is 0 which indicates it's
-// unknown). This is a nop on other platforms.
+// recorded. This is a nop on other platforms.
 void RecordHardFaultHistogram(int same_version_startup_count) {
 #if defined(OS_WIN)
   uint32_t hard_fault_count = 0;
 
   // Don't record histograms if unable to get the hard fault count.
   if (!GetHardFaultCountForCurrentProcess(&hard_fault_count))
     return;
 
-  std::string same_version_startup_count_suffix;
-  if (same_version_startup_count != 0) {
-    // Histograms below will be suffixed by |same_version_startup_count| up to
-    // |kMaxSameVersionCountRecorded|, higher counts will be grouped in the
-    // ".Over" suffix. Make sure to reflect changes to
-    // kMaxSameVersionCountRecorded in the "SameVersionStartupCounts" histogram
-    // suffix.
-    const int kMaxSameVersionCountRecorded = 9;
-    same_version_startup_count_suffix.push_back('.');
-    DCHECK_GE(same_version_startup_count, 1);
-    if (same_version_startup_count <= kMaxSameVersionCountRecorded) {
-      same_version_startup_count_suffix.append(
-          base::IntToString(same_version_startup_count));
-    } else {
-      same_version_startup_count_suffix.append("Over");
-    }
+  // Histograms below will be suffixed by |same_version_startup_count| up to
+  // |kMaxSameVersionCountRecorded|, higher counts will be grouped in the
+  // ".Over" suffix. Make sure to reflect changes to
+  // kMaxSameVersionCountRecorded in the "SameVersionStartupCounts" histogram
+  // suffix.
+  std::string same_version_startup_count_suffix(".");
+  constexpr int kMaxSameVersionCountRecorded = 9;
+  same_version_startup_count_suffix.push_back('.');

[gab, 2016/07/07 19:05:31]

It starts with a '.' on 203 this adds a second one.

Please verify the resulting histogram in chrome://histograms before landing.

[fdoray, 2016/07/08 14:20:21]

Done.

+  DCHECK_GE(same_version_startup_count, 1);
+  if (same_version_startup_count <= kMaxSameVersionCountRecorded) {
+    same_version_startup_count_suffix.append(
+        base::IntToString(same_version_startup_count));
+  } else {
+    same_version_startup_count_suffix.append("Over");
   }
 
   // Hard fault counts are expected to be in the thousands range,
   // corresponding to faulting in ~10s of MBs of code ~10s of KBs at a time.
   // (Observed to vary from 1000 to 10000 on various test machines and
   // platforms.)
   const char kHardFaultCountHistogram[] =
       "Startup.BrowserMessageLoopStartHardFaultCount";
   UMA_HISTOGRAM_CUSTOM_COUNTS(kHardFaultCountHistogram, hard_fault_count, 1,
                               40000, 50);
@@ skipping 313 matching lines @@
 void RecordExeMainEntryPointTime(const base::Time& time) {
   const std::string exe_load_ticks =
       base::Int64ToString(StartupTimeToTimeTicks(time).ToInternalValue());
   std::unique_ptr<base::Environment> env(base::Environment::Create());
   env->SetVar(kChromeMainTicksEnvVar, exe_load_ticks);
 }
 
 void RecordBrowserMainMessageLoopStart(const base::TimeTicks& ticks,
                                        bool is_first_run,
                                        PrefService* pref_service) {
-  int same_version_startup_count = 0;
-  if (pref_service)
-    same_version_startup_count = RecordSameVersionStartupCount(pref_service);
+  DCHECK(pref_service);
+
+  const int same_version_startup_count =
+      RecordSameVersionStartupCount(pref_service);
   // Keep RecordHardFaultHistogram() first as much as possible as many other
   // histograms depend on it setting |g_startup_temperature|.
   RecordHardFaultHistogram(same_version_startup_count);
   AddStartupEventsForTelemetry();
-  if (pref_service)
-    RecordTimeSinceLastStartup(pref_service);
+  RecordTimeSinceLastStartup(pref_service);
   RecordSystemUptimeHistogram();
   RecordMainEntryTimeHistogram();
 
   const base::TimeTicks& process_creation_ticks =
       g_process_creation_ticks.Get();
   if (!is_first_run && !process_creation_ticks.is_null()) {
     UMA_HISTOGRAM_AND_TRACE_WITH_STARTUP_TEMPERATURE(
         UMA_HISTOGRAM_LONG_TIMES_100, "Startup.BrowserMessageLoopStartTime",
         process_creation_ticks, ticks);
   }
@@ skipping 137 matching lines @@
 
 base::TimeTicks MainEntryPointTicks() {
   return g_browser_main_entry_point_ticks.Get();
 }
 
 StartupTemperature GetStartupTemperature() {
   return g_startup_temperature;
 }
 
 }  // namespace startup_metric_utils