Automatically set the overscan insets if the output has the flag and no preference is set.

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 292da15f898c56cde0745166b1aa001a83f3c70d..736aa8c4052484c940e7a812ae8a4d07eea7ac7b 100644
--- a/ash/display/display_manager.h
+++ b/ash/display/display_manager.h
@@ -141,6 +141,16 @@ class ASH_EXPORT DisplayManager : public aura::RootWindowObserver {
 
     // The overscan insets for the display.
     gfx::Insets overscan_insets_in_dip;
+
+    // True if the output overscans. False means unknown, it may or may not
+    // overscan.

[oshima, 2013/01/12 02:06:38]

True if we detect that the display has overscan area. False if the display
doesn't have it, or failed to detect it.

[Jun Mukai, 2013/01/14 18:18:51]

Done.

+    bool overscan;

[oshima, 2013/01/12 02:06:38]

has_overscan ?

(according to http://en.wikipedia.org/wiki/Overscan, "overscan" can mean the
area)

[Jun Mukai, 2013/01/14 18:18:51]

done.
# sometimes 'overscan' is used as verb, which is my intention. but
'has_overscan' would be better.

+
+    // True if the |overscan_insets_in_dip| is specified. This is set because
+    // the user may specify an empty intentionally.
+    bool overscan_insets_specified;

[oshima, 2013/01/12 02:06:38]

custom_overscan_insets ?

[Jun Mukai, 2013/01/14 18:18:51]

done.  has_custom_overscan_insets for consistency.

+
+    DisplayInfo();

[oshima, 2013/01/12 02:06:38]

move this to top

[Jun Mukai, 2013/01/14 18:18:51]

Done.

   };
 
   void Init();
@@ -162,8 +172,8 @@ class ASH_EXPORT DisplayManager : public aura::RootWindowObserver {
   // the center of the nearest display if it's outside of all displays.
   void EnsurePointerInDisplays();
 
-  // Updates |display_names_| by calling platform-dependent functions.
-  void RefreshDisplayNames();
+  // Updates |display_info_| by calling platform-dependent functions.
+  void RefreshDisplayInfo();
 
   // Update the display's id in the |display_list| to match the ones
   // stored in this display manager's |displays_|. This is used to