Fix sky include guards to match Chromium style

sky/engine/core/rendering/PaintPhase.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
-#ifndef PaintPhase_h
-#define PaintPhase_h
+#ifndef SKY_ENGINE_CORE_RENDERING_PAINTPHASE_H_
+#define SKY_ENGINE_CORE_RENDERING_PAINTPHASE_H_
 
 namespace blink {
 
 /*
  *  The painting of a layer occurs in three distinct phases.  Each phase involves
  *  a recursive descent into the layer's render objects. The first phase is the background phase.
  *  The backgrounds and borders of all blocks are painted.  Inlines are not painted at all.
  *  Floats must paint above block backgrounds but entirely below inline content that can overlap them.
  *  In the foreground phase, all inlines are fully painted.  Inline replaced elements will get all
  *  three phases invoked on them during this phase.
@@ skipping 21 matching lines @@
     PaintBehaviorFlattenCompositingLayers = 1 << 2,
     PaintBehaviorRenderingSVGMask = 1 << 3,
     PaintBehaviorSkipRootBackground = 1 << 4,
     PaintBehaviorRootBackgroundOnly = 1 << 5
 };
 
 typedef unsigned PaintBehavior;
 
 } // namespace blink
 
-#endif // PaintPhase_h
+#endif  // SKY_ENGINE_CORE_RENDERING_PAINTPHASE_H_