aura: Make 'ui' buildable without gtk.

ui/gfx/native_widget_types.h

Index: ui/gfx/native_widget_types.h
diff --git a/ui/gfx/native_widget_types.h b/ui/gfx/native_widget_types.h
index 9eeb0804a8856f623316aea702f8c4aa016dacfd..847671c61af7f38e22229a06a191b8ab913f71f9 100644
--- a/ui/gfx/native_widget_types.h
+++ b/ui/gfx/native_widget_types.h
@@ -60,9 +60,12 @@ class NSView;
 class NSWindow;
 class NSTextField;
 #endif  // __OBJC__
-#elif defined(USE_WAYLAND)
+#elif defined(OS_POSIX)
 typedef struct _PangoFontDescription PangoFontDescription;
 typedef struct _cairo cairo_t;
+#endif
+
+#if defined(USE_WAYLAND)
 typedef struct _GdkPixbuf GdkPixbuf;
 struct wl_egl_window;
 
@@ -73,13 +76,11 @@ class WaylandCursor;
 
 typedef struct _GdkRegion GdkRegion;
 #elif defined(TOOLKIT_USES_GTK)
-typedef struct _PangoFontDescription PangoFontDescription;
 typedef struct _GdkCursor GdkCursor;
 typedef struct _GdkPixbuf GdkPixbuf;
 typedef struct _GdkRegion GdkRegion;
 typedef struct _GtkWidget GtkWidget;
 typedef struct _GtkWindow GtkWindow;
-typedef struct _cairo cairo_t;
 #elif defined(OS_ANDROID)
 class ChromeView;
 #endif
@@ -129,7 +130,7 @@ typedef void* NativeMenu;
 // a Wayland specific region
 typedef GdkRegion* NativeRegion;
 typedef void* NativeViewAccessible;
-#elif defined(USE_X11)
+#elif defined(TOOLKIT_USES_GTK)
 typedef PangoFontDescription* NativeFont;
 typedef GtkWidget* NativeEditView;
 typedef cairo_t* NativeDrawingContext;
@@ -137,6 +138,14 @@ typedef GdkCursor* NativeCursor;
 typedef GtkWidget* NativeMenu;
 typedef GdkRegion* NativeRegion;
 typedef void* NativeViewAccessible;
+#elif defined(USE_AURA)
+typedef PangoFontDescription* NativeFont;
+typedef void* NativeEditView;
+typedef cairo_t* NativeDrawingContext;
+typedef void* NativeCursor;
+typedef void* NativeMenu;
+typedef void* NativeRegion;
+typedef void* NativeViewAccessible;
 #elif defined(OS_ANDROID)
 typedef void* NativeFont;
 typedef ChromeView* NativeView;
@@ -145,6 +154,7 @@ typedef void* NativeEditView;
 typedef void* NativeDrawingContext;
 typedef void* NativeCursor;
 typedef void* NativeMenu;
+typedef void* NativeRegion;
 typedef void* NativeViewAccessible;
 #endif