GTK: Turn on the GTK+ integration by default.

base/linux_util.cc

Index: base/linux_util.cc
diff --git a/base/linux_util.cc b/base/linux_util.cc
index 14c355e89f1d4cac8e9b781a27d7f5cc41d6bcc8..e49a01fce324f4b91047ff14b70340624ec13333 100644
--- a/base/linux_util.cc
+++ b/base/linux_util.cc
@@ -274,6 +274,8 @@ DesktopEnvironment GetDesktopEnvironment(EnvironmentVariableGetter* env) {
         return DESKTOP_ENVIRONMENT_KDE4;
       return DESKTOP_ENVIRONMENT_KDE3;
     }
+    else if (desktop_session == "xfce4")
+      return DESKTOP_ENVIRONMENT_XFCE;
   }
 
   // Fall back on some older environment variables.
@@ -300,6 +302,8 @@ const char* GetDesktopEnvironmentName(DesktopEnvironment env) {
       return "KDE3";
     case DESKTOP_ENVIRONMENT_KDE4:
       return "KDE4";
+    case DESKTOP_ENVIRONMENT_XFCE:
+      return "XFCE";
   }
   return NULL;
 }