cc: Remove cc::settings, move them to LayerTreeSettings.

cc/settings.h

-// Copyright 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.
-
-#ifndef CC_SETTINGS_H_
-#define CC_SETTINGS_H_
-
-#include "cc/cc_export.h"
-
-namespace cc {
-
-// This file is for settings that apply to all compositors.  Add settings to
-// LayerTreeSettings if a ui and renderer compositor might not want the same
-// setting.
-
-class CC_EXPORT Settings {
-public:
-    static bool perTilePaintingEnabled();
-    static bool partialSwapEnabled();
-    static bool acceleratedAnimationEnabled();
-    static bool pageScalePinchZoomEnabled();
-    static bool backgroundColorInsteadOfCheckerboard();
-    static bool traceOverdraw();
-
-    static void setPartialSwapEnabled(bool);
-    static void setPerTilePaintingEnabled(bool);
-    static void setAcceleratedAnimationEnabled(bool);
-    static void setPageScalePinchZoomEnabled(bool);
-
-    static void resetForTest();
-};
-
-} // namespace cc
-
-#endif  // CC_SETTINGS_H_