Lock rotation when screen is manually rotated.

ash/display/display_manager.h

Index: ash/display/display_manager.h
diff --git a/ash/display/display_manager.h b/ash/display/display_manager.h
index fcbd7dd844fc21ceecf74a5d980a9943cd34af25..0b865bf9fffbde65ac1b84112fe6f69053810433 100644
--- a/ash/display/display_manager.h
+++ b/ash/display/display_manager.h
@@ -14,6 +14,7 @@
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
+#include "ui/display/types/display_constants.h"
 #include "ui/gfx/display.h"
 
 #if defined(OS_CHROMEOS)
@@ -159,7 +160,8 @@ class ASH_EXPORT DisplayManager
   void SetOverscanInsets(int64 display_id, const gfx::Insets& insets_in_dip);
 
   // Sets the display's rotation.
-  void SetDisplayRotation(int64 display_id, gfx::Display::Rotation rotation);
+  void SetDisplayRotation(int64 display_id, gfx::Display::Rotation rotation,
+                          ui::RotationSource source);
 
   // Sets the display's ui scale.
   void SetDisplayUIScale(int64 display_id, float ui_scale);