Record shutdown type UMA

chrome/browser/browser_shutdown.cc

 // Copyright (c) 2012 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 "chrome/browser/browser_shutdown.h"
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
@@ skipping 65 matching lines @@
 Time* g_shutdown_started = nullptr;
 ShutdownType g_shutdown_type = NOT_VALID;
 int g_shutdown_num_processes;
 int g_shutdown_num_processes_slow;
 
 const char kShutdownMsFile[] = "chrome_shutdown_ms.txt";
 
 const char* ToShutdownTypeString(ShutdownType type) {
   switch (type) {
     case NOT_VALID:
+    case SHUTDOWN_TYPE_MAX_VALUE:
       NOTREACHED();
       return "";
     case WINDOW_CLOSE:
       return "close";
     case BROWSER_EXIT:
       return "exit";
     case END_SESSION:
       return "end";
   }
   return "";
@@ skipping 224 matching lines @@
   PrefService* prefs = g_browser_process->local_state();
   ShutdownType type =
       static_cast<ShutdownType>(prefs->GetInteger(prefs::kShutdownType));
   int num_procs = prefs->GetInteger(prefs::kShutdownNumProcesses);
   int num_procs_slow = prefs->GetInteger(prefs::kShutdownNumProcessesSlow);
   // clear the prefs immediately so we don't pick them up on a future run
   prefs->SetInteger(prefs::kShutdownType, NOT_VALID);
   prefs->SetInteger(prefs::kShutdownNumProcesses, 0);
   prefs->SetInteger(prefs::kShutdownNumProcessesSlow, 0);
 
+  UMA_HISTOGRAM_ENUMERATION("Shutdown.ShutdownType", type,
+                            SHUTDOWN_TYPE_MAX_VALUE);
+
   // Read and delete the file on the file thread.
   BrowserThread::PostTask(
       BrowserThread::FILE, FROM_HERE,
       base::Bind(&ReadLastShutdownFile, type, num_procs, num_procs_slow));
 }
 
 void SetTryingToQuit(bool quitting) {
   g_trying_to_quit = quitting;
 
   if (quitting)
@@ skipping 26 matching lines @@
     base::trace_event::TraceConfig trace_config(
         command_line.GetSwitchValueASCII(switches::kTraceShutdown), "");
     content::TracingController::GetInstance()->StartTracing(
         trace_config,
         content::TracingController::StartTracingDoneCallback());
   }
   TRACE_EVENT0("shutdown", "StartShutdownTracing");
 }
 
 }  // namespace browser_shutdown