Prevent DisplayPreferences from saving incorrect rotations.

ui/gfx/display.h

Index: ui/gfx/display.h
diff --git a/ui/gfx/display.h b/ui/gfx/display.h
index fe2a40cf632b6fa81c5fa7119b2f87b1574cef0e..7cee64ca5390fef85857e44680472cbd60644854 100644
--- a/ui/gfx/display.h
+++ b/ui/gfx/display.h
@@ -30,6 +30,13 @@ class GFX_EXPORT Display {
     ROTATE_270,
   };
 
+  // The cause of a change in display rotation.

[tdanderson, 2015/04/13 22:44:46]

Nit: For the ease of someone reading this for the first time, consider giving a
bit more context in the comment regarding what each of these mean.

[jonross, 2015/04/15 17:43:12]

Done.

+  enum RotationSource {
+    ROTATION_SOURCE_ACCELEROMETER = 0,
+    ROTATION_SOURCE_ACTIVE,
+    ROTATION_SOURCE_USER,
+  };
+
   // Touch support for the display.
   enum TouchSupport {
     TOUCH_SUPPORT_UNKNOWN,