Move some XDG code from chrome to base.

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 590 matching lines @@
   // TODO(akalin): Come up with unit tests for this.
   // TODO(akalin): Use for Linux, too?
   if (!HasACacheSubdir(path_)) {
     FilePath app_data_path, user_cache_path;
     if (PathService::Get(base::DIR_APP_DATA, &app_data_path) &&
         PathService::Get(base::DIR_CACHE, &user_cache_path) &&
         app_data_path.AppendRelativePath(path_, &user_cache_path)) {
       base_cache_path_ = user_cache_path;
     }
   }
+#elif defined(OS_POSIX)  // Posix minus Mac.
+  // See http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
+  // for a spec on where cache files go.  The net effect for most systems is we
+  // use ~/.cache/chromium/ for Chromium and ~/.cache/google-chrome/ for
+  // official builds.
+  if (!PathService::IsOverridden(chrome::DIR_USER_DATA)) {
+#if defined(GOOGLE_CHROME_BUILD)
+    const char kCacheDir[] = "google-chrome";
 #else
-  if (!PathService::IsOverridden(chrome::DIR_USER_DATA))
-    PathService::Get(chrome::DIR_USER_CACHE, &base_cache_path_);
+    const char kCacheDir[] = "chromium";
+#endif
+    PathService::Get(base::DIR_USER_CACHE, &base_cache_path_);
+    base_cache_path_ = base_cache_path_.Append(kCacheDir);
+    if (!file_util::PathExists(base_cache_path_))
+      file_util::CreateDirectory(base_cache_path_);
+  }
 #endif
   if (base_cache_path_.empty())
     base_cache_path_ = path_;
 
   // Listen for theme installation.
   registrar_.Add(this, NotificationType::THEME_INSTALLED,
                  NotificationService::AllSources());
 
   // Listen for bookmark model load, to bootstrap the sync service.
   registrar_.Add(this, NotificationType::BOOKMARK_MODEL_LOADED,
@@ skipping 666 matching lines @@
   }
   if (!sync_service_.get())
     InitSyncService();
   return sync_service_.get();
 }
 
 void ProfileImpl::InitSyncService() {
   sync_service_.reset(new ProfileSyncService(this));
   sync_service_->Initialize();
 }