Additional tracing and histogram in Extensions startup.

chrome/browser/extensions/extension_system_impl.cc

 // Copyright 2014 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/extensions/extension_system_impl.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 297 matching lines @@
   declarative_user_script_manager_.reset(
       new DeclarativeUserScriptManager(profile_));
 
   // ExtensionService depends on RuntimeData.
   runtime_data_.reset(new RuntimeData(ExtensionRegistry::Get(profile_)));
 
   bool autoupdate_enabled = !profile_->IsGuestSession();
 #if defined(OS_CHROMEOS)
   if (!extensions_enabled)
     autoupdate_enabled = false;
-#endif
+#endif  // defined(OS_CHROMEOS)
   extension_service_.reset(new ExtensionService(
       profile_, base::CommandLine::ForCurrentProcess(),
       profile_->GetPath().AppendASCII(extensions::kInstallDirectoryName),
       ExtensionPrefs::Get(profile_), Blacklist::Get(profile_),
       autoupdate_enabled, extensions_enabled, &ready_));
 
   // These services must be registered before the ExtensionService tries to
   // load any extensions.
   {
     install_verifier_.reset(
         new InstallVerifier(ExtensionPrefs::Get(profile_), profile_));
     install_verifier_->Init();
     content_verifier_ = new ContentVerifier(
         profile_, new ContentVerifierDelegateImpl(extension_service_.get()));
     ContentVerifierDelegate::Mode mode =
         ContentVerifierDelegateImpl::GetDefaultMode();
 #if defined(OS_CHROMEOS)
     mode = std::max(mode, ContentVerifierDelegate::BOOTSTRAP);
-#endif
+#endif  // defined(OS_CHROMEOS)
     if (mode >= ContentVerifierDelegate::BOOTSTRAP)
       content_verifier_->Start();
     info_map()->SetContentVerifier(content_verifier_.get());
 
     management_policy_.reset(new ManagementPolicy);
     RegisterManagementPolicyProviders();
   }
 
   bool skip_session_extensions = false;
 #if defined(OS_CHROMEOS)
@@ skipping 246 matching lines @@
 void ExtensionSystemImpl::UnregisterExtensionWithRequestContexts(
     const std::string& extension_id,
     const UnloadedExtensionInfo::Reason reason) {
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&InfoMap::RemoveExtension, info_map(), extension_id, reason));
 }
 
 }  // namespace extensions