Store rotation/ui scale to local state.

ash/display/display_change_observer_x11.cc

Index: ash/display/display_change_observer_x11.cc
diff --git a/ash/display/display_change_observer_x11.cc b/ash/display/display_change_observer_x11.cc
index 3f3f9bba6f127aa3fbe51a10d1fb66533aad3ee4..7bde515a7b8dddbd5f9dabe2c74aa9bc36e9f702 100644
--- a/ash/display/display_change_observer_x11.cc
+++ b/ash/display/display_change_observer_x11.cc
@@ -196,6 +196,9 @@ void DisplayChangeObserverX11::OnDisplayModeChanged() {
     displays.push_back(DisplayInfo(id, name, has_overscan));
     displays.back().set_device_scale_factor(device_scale_factor);
     displays.back().SetBounds(display_bounds);
+    // Invalidate ui_scale (and rotation) so that DisplayInfo::CopyFromNative
+    // ignores ui_scale and rotate value.
+    displays.back().set_ui_scale(0.0f);

[Jun Mukai, 2013/03/22 00:53:07]

setting a scale to '0' sounds awful to me. Why not 1.0f?

[oshima, 2013/03/22 02:06:51]

because 1.0f is valid scale. I understand that this may be confusing a bit. I
made it explicit flag.

   }
 
   // Free all allocated resources.