Extract InstallVerifier from ExtensionSystem.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 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 "chrome/browser/extensions/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 724 matching lines @@
 
   syncer::SyncChange sync_change;
   // Don't sync the uninstall if we're going to reinstall the extension
   // momentarily.
   if (extension_sync_service_ &&
       reason != extensions::UNINSTALL_REASON_REINSTALL) {
      sync_change = extension_sync_service_->PrepareToSyncUninstallExtension(
         extension.get(), is_ready());
   }
 
-  system_->install_verifier()->Remove(extension->id());
+  InstallVerifier::Get(GetBrowserContext())->Remove(extension->id());
 
   UMA_HISTOGRAM_ENUMERATION("Extensions.UninstallType",
                             extension->GetType(), 100);
   RecordPermissionMessagesHistogram(extension.get(), "Uninstall");
 
   // Unload before doing more cleanup to ensure that nothing is hanging on to
   // any of these resources.
   UnloadExtension(extension->id(), UnloadedExtensionInfo::REASON_UNINSTALL);
 
   // Tell the backend to start deleting installed extensions on the file thread.
@@ skipping 1150 matching lines @@
     Extension::State initial_state,
     int install_flags,
     const syncer::StringOrdinal& page_ordinal,
     const std::string& install_parameter) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   bool was_ephemeral = extension_prefs_->IsEphemeralApp(extension->id());
   extension_prefs_->OnExtensionInstalled(
       extension, initial_state, page_ordinal, install_flags, install_parameter);
   delayed_installs_.Remove(extension->id());
   if (InstallVerifier::NeedsVerification(*extension))
-    system_->install_verifier()->VerifyExtension(extension->id());
+    InstallVerifier::Get(GetBrowserContext())->VerifyExtension(extension->id());
 
   const Extension* old = GetInstalledExtension(extension->id());
   if (extensions::AppDataMigrator::NeedsMigration(old, extension)) {
     app_data_migrator_->DoMigrationAndReply(
         old, extension,
         base::Bind(&ExtensionService::FinishInstallation, AsWeakPtr(),
                    make_scoped_refptr(extension), was_ephemeral));
     return;
   }
 
@@ skipping 671 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }