diff -r 000000000000 -r 6474c204b198 testing/tools/screenshot/gdk-screenshot.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/testing/tools/screenshot/gdk-screenshot.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,158 @@
+/*
+ * Copyright (c) 2009, The Mozilla Foundation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the Mozilla Foundation nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY The Mozilla Foundation ''AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL The Mozilla Foundation BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Contributors:
+ *   Ted Mielczarek <ted.mielczarek@gmail.com>
+ *   Karl Tomlinson <karlt+@karlt.net>
+ */
+/*
+ * gdk-screenshot.cpp: Save a screenshot of the root window in .png format.
+ *  If a filename is specified as the first argument on the commandline,
+ *  then the image will be saved to that filename. Otherwise, the image will
+ *  be written to stdout.
+ */
+#include <gdk/gdk.h>
+#include <gdk/gdkx.h>
+#ifdef HAVE_LIBXSS
+#include <X11/extensions/scrnsaver.h>
+#endif
+
+#include <errno.h>
+#include <stdio.h>
+#include "mozilla/NullPtr.h"
+
+gboolean save_to_stdout(const gchar *buf, gsize count,
+                        GError **error, gpointer data)
+{
+  size_t written = fwrite(buf, 1, count, stdout);
+  if (written != count) {
+    g_set_error(error, G_FILE_ERROR, g_file_error_from_errno(errno),
+                "Write to stdout failed: %s", g_strerror(errno));
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
+int main(int argc, char** argv)
+{
+  gdk_init(&argc, &argv);
+
+// TODO GTK3
+#if defined(HAVE_LIBXSS) && (MOZ_WIDGET_GTK == 2)
+  int event_base, error_base;
+  Bool have_xscreensaver =
+    XScreenSaverQueryExtension(GDK_DISPLAY(), &event_base, &error_base);
+
+  if (!have_xscreensaver) {
+    fprintf(stderr, "No XScreenSaver extension on display\n");
+  } else {
+    XScreenSaverInfo* info = XScreenSaverAllocInfo();
+    if (!info) {
+      fprintf(stderr, "%s: Out of memory\n", argv[0]);
+      return 1;
+    }
+    XScreenSaverQueryInfo(GDK_DISPLAY(), GDK_ROOT_WINDOW(), info);
+
+    const char* state;
+    const char* til_or_since = nullptr;
+    switch (info->state) {
+    case ScreenSaverOff:
+      state = "Off";
+      til_or_since = "XScreenSaver will activate after another %lu seconds idle time\n";
+      break;
+    case ScreenSaverOn:
+      state = "On";
+      if (info->til_or_since) {
+        til_or_since = "XScreenSaver idle timer activated %lu seconds ago\n";
+      } else {
+        til_or_since = "XScreenSaver idle activation is disabled\n";
+      }
+      break;
+    case ScreenSaverDisabled:
+      state = "Disabled";
+      break;
+    default:
+      state = "unknown";
+    }
+
+    const char* kind;
+    switch (info->kind) {
+    case ScreenSaverBlanked:
+      kind = "Blanked";
+      break;
+    case ScreenSaverInternal:
+      state = "Internal";
+      break;
+    case ScreenSaverExternal:
+      state = "External";
+      break;
+    default:
+      state = "unknown";
+    }
+
+    fprintf(stderr, "XScreenSaver state: %s\n", state);
+
+    if (til_or_since) {
+      fprintf(stderr, "XScreenSaver kind: %s\n", kind);
+      fprintf(stderr, til_or_since, info->til_or_since / 1000);
+    }
+
+    fprintf(stderr, "User input has been idle for %lu seconds\n", info->idle / 1000);
+
+    XFree(info);
+  }
+#endif
+
+  GdkWindow* window = gdk_get_default_root_window();
+  GdkPixbuf* screenshot = nullptr;
+// TODO GTK3
+#if (MOZ_WIDGET_GTK == 2)
+  screenshot = gdk_pixbuf_get_from_drawable(nullptr, window, nullptr,
+                                            0, 0, 0, 0,
+                                            gdk_screen_width(),
+                                            gdk_screen_height());
+#endif
+  if (!screenshot) {
+    fprintf(stderr, "%s: failed to create screenshot GdkPixbuf\n", argv[0]);
+    return 1;
+  }
+
+  GError* error = nullptr;
+  if (argc > 1) {
+    gdk_pixbuf_save(screenshot, argv[1], "png", &error, nullptr);
+  } else {
+    gdk_pixbuf_save_to_callback(screenshot, save_to_stdout, nullptr,
+                                "png", &error, nullptr);
+  }
+  if (error) {
+    fprintf(stderr, "%s: failed to write screenshot as png: %s\n",
+            argv[0], error->message);
+    return error->code;
+  }
+
+  return 0;
+}