Do not rely on XDG_CURRENT_DESKTOP only when testing for Unity.

base/nix/xdg_util.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 "base/nix/xdg_util.h"
 
 #include <string>
 
 #include "base/base_paths.h"
 #include "base/environment.h"
@@ skipping 39 matching lines @@
     path = path.Append(fallback_dir);
   }
   return path.StripTrailingSeparators();
 }
 
 DesktopEnvironment GetDesktopEnvironment(Environment* env) {
   // XDG_CURRENT_DESKTOP is the newest standard circa 2012.
   std::string xdg_current_desktop;
   if (env->GetVar("XDG_CURRENT_DESKTOP", &xdg_current_desktop)) {
     // Not all desktop environments set this env var as of this writing.
-    if (xdg_current_desktop == "Unity")
+    if (xdg_current_desktop == "Unity") {
+      // gnome-fallback sessions set XDG_CURRENT_DESKTOP to Unity
+      // DESKTOP_SESSION can be gnome-fallback or gnome-fallback-compiz
+      std::string desktop_session;
+      if (env->GetVar("DESKTOP_SESSION", &desktop_session) &&
+          desktop_session.find("gnome-fallback") != std::string::npos) {
+        return DESKTOP_ENVIRONMENT_GNOME;
+      }
       return DESKTOP_ENVIRONMENT_UNITY;
-    else if (xdg_current_desktop == "GNOME")
+    } else if (xdg_current_desktop == "GNOME") {
       return DESKTOP_ENVIRONMENT_GNOME;
+    }
   }
 
   // DESKTOP_SESSION was what everyone used in 2010.
   std::string desktop_session;
   if (env->GetVar("DESKTOP_SESSION", &desktop_session)) {
     if (desktop_session == "gnome") {
       return DESKTOP_ENVIRONMENT_GNOME;
     } else if (desktop_session == "kde4") {
       return DESKTOP_ENVIRONMENT_KDE4;
     } else if (desktop_session == "kde") {
@@ skipping 37 matching lines @@
   }
   return NULL;
 }
 
 const char* GetDesktopEnvironmentName(Environment* env) {
   return GetDesktopEnvironmentName(GetDesktopEnvironment(env));
 }
 
 }  // namespace nix
 }  // namespace base