linux_aura: Default to system titlebars under some window managers.

ui/base/x/x11_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.
 
 // This file defines utility functions for X11 (Linux only). This code has been
 // ported from XCB since we can't use XCB on Ubuntu while its 32-bit support
 // remains woefully incomplete.
 
 #include "ui/base/x/x11_util.h"
 
@@ skipping 993 matching lines @@
   while (true) {
     XID parent = GetParentWindow(window);
     if (parent == None)
       return None;
     if (parent == root)
       return window;
     window = parent;
   }
 }
 
+bool GetCustomFramePrefDefault() {
+  // Ideally, we'd use the custom frame by default and just fall back on using
+  // system decorations for the few (?) tiling window managers where the custom
+  // frame doesn't make sense (e.g. awesome, ion3, ratpoison, xmonad, etc.) or
+  // other WMs where it has issues (e.g. Fluxbox -- see issue 19130).  The EWMH
+  // _NET_SUPPORTING_WM property makes it easy to look up a name for the current
+  // WM, but at least some of the WMs in the latter group don't set it.
+  // Instead, we default to using system decorations for all WMs and
+  // special-case the ones where the custom frame should be used.
+  ui::WindowManagerName wm_type = GuessWindowManager();
+  return (wm_type == WM_BLACKBOX ||
+          wm_type == WM_COMPIZ ||
+          wm_type == WM_ENLIGHTENMENT ||
+          wm_type == WM_METACITY ||
+          wm_type == WM_MUFFIN ||
+          wm_type == WM_MUTTER ||
+          wm_type == WM_OPENBOX ||
+          wm_type == WM_XFWM4);
+}
+
 bool GetWindowDesktop(XID window, int* desktop) {
   return GetIntProperty(window, "_NET_WM_DESKTOP", desktop);
 }
 
 std::string GetX11ErrorString(XDisplay* display, int err) {
   char buffer[256];
   XGetErrorText(display, err, buffer, arraysize(buffer));
   return buffer;
 }
 
@@ skipping 535 matching lines @@
       << "request_code " << static_cast<int>(error_event.request_code) << ", "
       << "minor_code " << static_cast<int>(error_event.minor_code)
       << " (" << request_str << ")";
 }
 
 // ----------------------------------------------------------------------------
 // End of x11_util_internal.h
 
 
 }  // namespace ui