Set the WM_CLASS property of X11 windows in Linux Aura build.

ui/base/x/x11_util.h

Index: ui/base/x/x11_util.h
diff --git a/ui/base/x/x11_util.h b/ui/base/x/x11_util.h
index f0cf1b7ef64951a2972226a45a2ac034c35e5c77..40eb9c5ec8752bd7df333220602a304e25308b2b 100644
--- a/ui/base/x/x11_util.h
+++ b/ui/base/x/x11_util.h
@@ -211,6 +211,12 @@ UI_EXPORT bool SetAtomArrayProperty(XID window,
 // Gets the X atom for default display corresponding to atom_name.
 Atom GetAtom(const char* atom_name);
 
+// Sets the WM_CLASS attribute for a given X11 window.
+UI_EXPORT void SetWindowClassHint(Display* display,
+                                  XID window,
+                                  std::string res_name,
+                                  std::string res_class);
+
 // Get |window|'s parent window, or None if |window| is the root window.
 UI_EXPORT XID GetParentWindow(XID window);