shell_integration_linux: Follow the XDG Base Directory Specification.

chrome/browser/shell_integration_linux.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/shell_integration_linux.h"
 
 #include <fcntl.h>
 #include <glib.h>
 #include <stdlib.h>
 #include <sys/stat.h>
@@ skipping 445 matching lines @@
   return "chromium-browser.desktop";
 #endif
 }
 
 bool GetDesktopShortcutTemplate(base::Environment* env,
                                 std::string* output) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
 
   std::vector<base::FilePath> search_paths;
 
+  // Search paths as specified in the XDG Base Directory Specification.
+  // http://standards.freedesktop.org/basedir-spec/latest/
   std::string xdg_data_home;
+  std::string home;
   if (env->GetVar("XDG_DATA_HOME", &xdg_data_home) &&
       !xdg_data_home.empty()) {
     search_paths.push_back(base::FilePath(xdg_data_home));
+  } else if (env->GetVar("HOME", &home) && !home.empty()) {
+    search_paths.push_back(base::FilePath(home).Append(".local").Append(
+        "share"));
   }
 
   std::string xdg_data_dirs;
   if (env->GetVar("XDG_DATA_DIRS", &xdg_data_dirs) &&
       !xdg_data_dirs.empty()) {
     base::StringTokenizer tokenizer(xdg_data_dirs, ":");
     while (tokenizer.GetNext()) {
       base::FilePath data_dir(tokenizer.token());
       search_paths.push_back(data_dir);
-      search_paths.push_back(data_dir.Append("applications"));
     }
+  } else {
+    search_paths.push_back(base::FilePath("/usr/local/share"));
+    search_paths.push_back(base::FilePath("/usr/share"));
   }
 
-  // Add some fallback paths for systems which don't have XDG_DATA_DIRS or have
-  // it incomplete.
-  search_paths.push_back(base::FilePath("/usr/share/applications"));
-  search_paths.push_back(base::FilePath("/usr/local/share/applications"));
-
   std::string template_filename(GetDesktopName(env));
   for (std::vector<base::FilePath>::const_iterator i = search_paths.begin();
        i != search_paths.end(); ++i) {
-    base::FilePath path = i->Append(template_filename);
+    base::FilePath path = i->Append("applications").Append(template_filename);
     VLOG(1) << "Looking for desktop file template in " << path.value();
     if (file_util::PathExists(path)) {
       VLOG(1) << "Found desktop file template at " << path.value();
       return file_util::ReadFileToString(path, output);
     }
   }
 
   LOG(ERROR) << "Could not find desktop file template.";
   return false;
 }
@@ skipping 223 matching lines @@
 
   base::FilePath shortcut_filename = GetExtensionShortcutFilename(
       profile_path, extension_id);
   DCHECK(!shortcut_filename.empty());
 
   DeleteShortcutOnDesktop(shortcut_filename);
   DeleteShortcutInApplicationsMenu(shortcut_filename);
 }
 
 }  // namespace ShellIntegrationLinux