Revert to enumerating all X windows if the Window Manager doesn't support _NE...

chrome/common/x11_util.cc

 // Copyright (c) 2009 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 "chrome/common/x11_util.h"
 
@@ skipping 143 matching lines @@
     return false;
 
   if (!XTranslateCoordinates(GetSecondaryDisplay(), window, root,
                              0, 0, &x, &y, &child))
     return false;
 
   *rect = gfx::Rect(x, y, width, height);
   return true;
 }
 
+bool EnumerateAllWindows(EnumerateWindowsDelegate* delegate) {
+  XID root = GetX11RootWindow();
+  XID parent;
+  XID* children;
+  unsigned int num_children;
+  int status = XQueryTree(GetXDisplay(), root, &root, &parent,
+                          &children, &num_children);
+  if (status == 0)
+    return false;
+
+  for (unsigned int i = 0; i < num_children; i++) {
+    if (delegate->ShouldStopIterating(children[i]))
+      break;
+  }
+
+  XFree(children);
+  return true;
+}
+
 XRenderPictFormat* GetRenderVisualFormat(Display* dpy, Visual* visual) {
   static XRenderPictFormat* pictformat = NULL;
   if (pictformat)
     return pictformat;
 
   DCHECK(QueryRenderSupport(dpy));
 
   pictformat = XRenderFindVisualFormat(dpy, visual);
   CHECK(pictformat) << "XRENDER does not support default visual";
 
@@ skipping 118 matching lines @@
     return false;
 
   if (children)
     XFree(children);
 
   *parent_is_root = root_window == *parent_window;
   return true;
 }
 
 }  // namespace x11_util