Gtk3 ui: Add libgtk3ui as a separate build component

chrome/browser/ui/libgtkui/skia_utils_gtk2.h

 // Copyright (c) 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 CHROME_BROWSER_UI_LIBGTK2UI_SKIA_UTILS_GTK2_H_
-#define CHROME_BROWSER_UI_LIBGTK2UI_SKIA_UTILS_GTK2_H_
+#ifndef CHROME_BROWSER_UI_LIBGTKUI_SKIA_UTILS_GTK2_H_
+#define CHROME_BROWSER_UI_LIBGTKUI_SKIA_UTILS_GTK2_H_
 
 #include <stdint.h>
 
 #include "third_party/skia/include/core/SkColor.h"
 
 typedef struct _GdkColor GdkColor;
 typedef struct _GdkPixbuf GdkPixbuf;
 
 class SkBitmap;
 
 // Define a macro for creating GdkColors from RGB values.  This is a macro to
 // allow static construction of literals, etc.  Use this like:
 //   GdkColor white = GDK_COLOR_RGB(0xff, 0xff, 0xff);
-#define GDK_COLOR_RGB(r, g, b) {0, r * ::libgtk2ui::kSkiaToGDKMultiplier,  \
-        g * ::libgtk2ui::kSkiaToGDKMultiplier,                          \
-        b * ::libgtk2ui::kSkiaToGDKMultiplier}
+#define GDK_COLOR_RGB(r, g, b) {0, r * ::libgtkui::kSkiaToGDKMultiplier,  \
+        g * ::libgtkui::kSkiaToGDKMultiplier,                          \
+        b * ::libgtkui::kSkiaToGDKMultiplier}
 
-namespace libgtk2ui {
+namespace libgtkui {
 
 // Multiply uint8_t color components by this.
 const int kSkiaToGDKMultiplier = 257;
 
 // Converts GdkColors to the ARGB layout Skia expects.
 SkColor GdkColorToSkColor(GdkColor color);
 
 // Converts ARGB to GdkColor.
 GdkColor SkColorToGdkColor(SkColor color);
 
 const SkBitmap GdkPixbufToImageSkia(GdkPixbuf* pixbuf);
 
 // Convert and copy a SkBitmap to a GdkPixbuf. NOTE: this uses BGRAToRGBA, so
 // it is an expensive operation.  The returned GdkPixbuf will have a refcount of
 // 1, and the caller is responsible for unrefing it when done.
 GdkPixbuf* GdkPixbufFromSkBitmap(const SkBitmap& bitmap);
 
-}  // namespace libgtk2ui
+}  // namespace libgtkui
 
-#endif  // CHROME_BROWSER_UI_LIBGTK2UI_SKIA_UTILS_GTK2_H_
+#endif  // CHROME_BROWSER_UI_LIBGTKUI_SKIA_UTILS_GTK2_H_