shell_integration_linux: Follow the XDG Base Directory Specification.

chrome/browser/shell_integration_linux.cc

Index: chrome/browser/shell_integration_linux.cc
diff --git a/chrome/browser/shell_integration_linux.cc b/chrome/browser/shell_integration_linux.cc
index e7412aeff0f09a63a6101a00455ca726283a20c8..d8f7d7bbe0aa9857d75eee0ee70184c72ca95ca2 100644
--- a/chrome/browser/shell_integration_linux.cc
+++ b/chrome/browser/shell_integration_linux.cc
@@ -463,10 +463,16 @@ bool GetDesktopShortcutTemplate(base::Environment* env,
 
   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;
@@ -476,19 +482,16 @@ bool GetDesktopShortcutTemplate(base::Environment* env,
     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();