Delete unused themes from disk on shutdown.

chrome/browser/profile.cc

 // Copyright (c) 2006-2008 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/profile.h"
 
 #include "app/theme_provider.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
@@ skipping 793 matching lines @@
 
   // FaviconService depends on HistoryServce so make sure we delete
   // HistoryService first.
   favicon_service_ = NULL;
 
   extension_message_service_->ProfileDestroyed();
 
   if (extensions_service_)
     extensions_service_->ProfileDestroyed();
 
+  // This causes the Preferences file to be written to disk.
   MarkAsCleanShutdown();
 }
 
 ProfileId ProfileImpl::GetRuntimeId() {
   return reinterpret_cast<ProfileId>(this);
 }
 
 FilePath ProfileImpl::GetPath() {
   return path_;
 }
@@ skipping 583 matching lines @@
 #endif
   return NULL;
 }
 
 void ProfileImpl::InitSyncService() {
 #if defined(BROWSER_SYNC)
   sync_service_.reset(new ProfileSyncService(this));
   sync_service_->Initialize();
 #endif
 }