Do not show notifications when in fullscreen or screensaver mode....

chrome/browser/fullscreen_linux.cc

+// Copyright (c) 2011 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.
+
+#include "chrome/browser/fullscreen.h"
+
+#include <gdk/gdk.h>
+#include <gdk/gdkx.h>
+
+#include <algorithm>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "chrome/browser/ui/gtk/gtk_util.h"
+#include "gfx/rect.h"
+#include "ui/base/x/x11_util.h"
+
+namespace {
+
+class TopMostWindowFinder : public ui::EnumerateWindowsDelegate {
+ public:
+  TopMostWindowFinder()
+      : top_most_window_(None) {}
+
+  XID top_most_window() const { return top_most_window_; }
+
+ protected:
+   virtual bool ShouldStopIterating(XID window) {
+     if (!ui::IsWindowVisible(window))
+       return false;
+     top_most_window_ = window;
+     return true;
+   }
+
+ private:
+  XID top_most_window_;
+
+  DISALLOW_COPY_AND_ASSIGN(TopMostWindowFinder);
+};
+
+bool IsTopMostWindowFullScreen() {
+  // Find the topmost window.
+  TopMostWindowFinder finder;
+  gtk_util::EnumerateTopLevelWindows(&finder);
+  XID window = finder.top_most_window();
+  if (window == None)
+    return false;
+
+  // Make sure it is not the desktop window.
+  static Atom atom = gdk_x11_get_xatom_by_name_for_display(
+      gdk_display_get_default(), "_NET_WM_WINDOW_TYPE_DESKTOP");
+
+  std::vector<Atom> atom_properties;
+  if (ui::GetAtomArrayProperty(window,
+                               "_NET_WM_WINDOW_TYPE",
+                               &atom_properties) &&
+      std::find(atom_properties.begin(), atom_properties.end(), atom)
+          != atom_properties.end())
+    return false;
+
+  // If it is a GDK window, check it using gdk function.
+  GdkWindow* gwindow = gdk_window_lookup(window);
+  if (gwindow && window != GDK_ROOT_WINDOW())
+    return gdk_window_get_state(gwindow) == GDK_WINDOW_STATE_FULLSCREEN;
+
+  // Otherwise, do the check via xlib function.
+  return ui::IsX11WindowFullScreen(window);
+}
+
+}
+
+bool IsFullScreenMode() {
+  gdk_error_trap_push();
+  bool result = IsTopMostWindowFullScreen();
+  bool got_error = gdk_error_trap_pop();
+  return result && !got_error;
+}