Screen Orientation API: cleanup, simplify and fix implementation.

public/platform/WebScreenOrientation.h

Index: public/platform/WebScreenOrientation.h
diff --git a/public/platform/WebScreenOrientation.h b/public/platform/WebScreenOrientation.h
index ed9684c8fc15c6139b7e8992ccfd9565ee836c5a..e4b811168f9d1046f3d714ea56b73fee03f0e635 100644
--- a/public/platform/WebScreenOrientation.h
+++ b/public/platform/WebScreenOrientation.h
@@ -5,14 +5,10 @@
 #ifndef WebScreenOrientation_h
 #define WebScreenOrientation_h
 
-namespace blink {
+#include "WebScreenOrientationType.h"
+#define WebScreenOrientation WebScreenOrientationType
 
-enum WebScreenOrientation {
-    WebScreenOrientationPortraitPrimary = 1,
-    WebScreenOrientationLandscapePrimary = 1 << 1,
-    WebScreenOrientationPortraitSecondary = 1 << 2,
-    WebScreenOrientationLandscapeSecondary = 1 << 3,
-};
+namespace blink {
 
 typedef unsigned char WebScreenOrientations;