Add debug shortcuts that toggles options to shows paint rects

ash/debug.cc

Index: ash/debug.cc
diff --git a/ash/debug.cc b/ash/debug.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ce2ca17da6c1ea50b9d27e944e8a2082f084a918
--- /dev/null
+++ b/ash/debug.cc
@@ -0,0 +1,28 @@
+// Copyright (c) 2013 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 "ash/debug.h"
+
+#include "ash/shell.h"
+#include "ui/aura/root_window.h"
+#include "ui/compositor/compositor.h"
+
+namespace ash {
+namespace debug {
+
+void ToggleShowPaintRects() {
+  Shell::RootWindowList root_windows =
+      Shell::GetInstance()->GetAllRootWindows();
+  scoped_ptr<bool> value;
+  for (Shell::RootWindowList::iterator it = root_windows.begin();
+       it != root_windows.end(); ++it) {
+    ui::Compositor* compositor = (*it)->compositor();
+    if (!value.get())
+      value.reset(new bool(!compositor->IsShowPaintRectsEnabled()));
+    compositor->SetShowPaintRectsEnabled(*value.get());
+  }
+}
+
+}  // debug
+}  // ash