Add a non-blocking "OneShotEvent" class

chrome/browser/extensions/extension_system.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/extensions/extension_system.h"
 
 #include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ skipping 133 matching lines @@
         !command_line->HasSwitch(chromeos::switches::kGuestSession);
 #endif
   extension_service_.reset(new ExtensionService(
       profile_,
       CommandLine::ForCurrentProcess(),
       profile_->GetPath().AppendASCII(ExtensionService::kInstallDirectoryName),
       extension_prefs_.get(),
       blacklist_.get(),
       autoupdate_enabled,
       extensions_enabled));
+  extension_service_->ready().RunAfter(
+      FROM_HERE, base::Bind(&AsyncEvent::MarkHappened, ready_.AsWeakPtr()));

[Matt Perry, 2013/05/15 21:08:54]

I think it will get confusing to have 2 "ready" signals for extensions. All of
extensions should become ready at the same time. I don't have a strong opinion
which class should hold the |ready| object, but only one of them should.

[Jeffrey Yasskin, 2013/05/15 22:46:50]

Ok, I've moved them into ExtensionSystem. They need to be there instead of
ExtensionService because many users want to schedule something to happen after
'ready' when the ExtensionService might not have been created yet.

 
   // These services must be registered before the ExtensionService tries to
   // load any extensions.
   {
     management_policy_.reset(new ManagementPolicy);
     RegisterManagementPolicyProviders();
   }
 
   bool skip_session_extensions = false;
 #if defined(OS_CHROMEOS)
@@ skipping 265 matching lines @@
 }
 
 ExtensionWarningService* ExtensionSystemImpl::warning_service() {
   return shared_->warning_service();
 }
 
 Blacklist* ExtensionSystemImpl::blacklist() {
   return shared_->blacklist();
 }
 
+const AsyncEvent& ExtensionSystemImpl::ready() const {
+  return shared_->ready();
+}
+
 void ExtensionSystemImpl::RegisterExtensionWithRequestContexts(
     const Extension* extension) {
   base::Time install_time;
   if (extension->location() != Manifest::COMPONENT) {
     install_time = extension_service()->extension_prefs()->
         GetInstallTime(extension->id());
   }
   bool incognito_enabled =
       extension_service()->IsIncognitoEnabled(extension->id());
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&ExtensionInfoMap::AddExtension, info_map(),
                  make_scoped_refptr(extension), install_time,
                  incognito_enabled));
 }
 
 void ExtensionSystemImpl::UnregisterExtensionWithRequestContexts(
     const std::string& extension_id,
     const extension_misc::UnloadedExtensionReason reason) {
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&ExtensionInfoMap::RemoveExtension, info_map(),
                  extension_id, reason));
 }
 
 }  // namespace extensions