Lock rotation when screen is manually rotated.

ui/display/types/display_constants.h

Index: ui/display/types/display_constants.h
diff --git a/ui/display/types/display_constants.h b/ui/display/types/display_constants.h
index cf4ee6030d18902047824980843831111836b856..3f682958a0b442b7b190daeb9d658b249141892f 100644
--- a/ui/display/types/display_constants.h
+++ b/ui/display/types/display_constants.h
@@ -47,6 +47,15 @@ enum ColorCalibrationProfile {
   NUM_COLOR_PROFILES,
 };
 
+// Define the cause of a rotation being applied to a display. Users can specify
+// rotations via "ctrl+shift+F3" or via the display settings. While Maximize
+// Mode is enabled the accelerometer will apply changes to the display
+// rotation.
+enum RotationSource {
+  USER,

[flackr, 2014/05/16 16:00:22]

We tend to have enum values which make it obvious what the enum is, like
ROTATION_SOURCE_USER

[jonross, 2014/05/20 15:24:30]

Done.

+  ACCELEROMETER,
+};

[oshima, 2014/05/17 03:23:30]

I'd like to avoid having this info in ui/display. Let me think about it over
weekends.

[jonross, 2014/05/20 15:24:30]

Will update the location once this has been decided upon.

+
 }  // namespace ui
 
 #endif  // UI_DISPLAY_TYPES_DISPLAY_CONSTANTS_H_