Fix device_event_log component build, make NonThreadSafe (Take 2)

chrome/browser/chrome_browser_main.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/chrome_browser_main.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 779 matching lines @@
 
 void ChromeBrowserMainParts::ToolkitInitialized() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::ToolkitInitialized");
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->ToolkitInitialized();
 }
 
 void ChromeBrowserMainParts::PreMainMessageLoopStart() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PreMainMessageLoopStart");
 
-  device_event_log::Initialize(0 /* default max entries */);
-
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->PreMainMessageLoopStart();
 }
 
 void ChromeBrowserMainParts::PostMainMessageLoopStart() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PostMainMessageLoopStart");
+
+  // device_event_log must be initialized after the message loop. Calls to
+  // {DEVICE}_LOG prior to here will only be logged with VLOG. Some
+  // platforms (e.g. chromeos) may have already initialized this.
+  if (!device_event_log::IsInitialized())
+    device_event_log::Initialize(0 /* default max entries */);
+
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->PostMainMessageLoopStart();
 }
 
 int ChromeBrowserMainParts::PreCreateThreads() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PreCreateThreads");
   result_code_ = PreCreateThreadsImpl();
 
   if (result_code_ == content::RESULT_CODE_NORMAL_EXIT) {
 #if !defined(OS_ANDROID)
@@ skipping 975 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }