Revert of Save and restore unified mode

ash/display/display_layout.cc

Index: ash/display/display_layout.cc
diff --git a/ash/display/display_layout.cc b/ash/display/display_layout.cc
index 9d8942ed13441a31675d8629cc5390e7c34d2f03..a733e762a8242a5e3d1b3b56e326a5c129cc6a34 100644
--- a/ash/display/display_layout.cc
+++ b/ash/display/display_layout.cc
@@ -24,7 +24,6 @@
 const char kPositionKey[] = "position";
 const char kOffsetKey[] = "offset";
 const char kMirroredKey[] = "mirrored";
-const char kDefaultUnifiedKey[] = "default_unified";
 const char kPrimaryIdKey[] = "primary-id";
 
 typedef std::map<DisplayLayout::Position, std::string> PositionToStringMap;
@@ -70,7 +69,6 @@
     : position(RIGHT),
       offset(0),
       mirrored(false),
-      default_unified(false),
       primary_id(gfx::Display::kInvalidDisplayID) {
 }
 
@@ -78,7 +76,6 @@
     : position(position),
       offset(offset),
       mirrored(false),
-      default_unified(false),
       primary_id(gfx::Display::kInvalidDisplayID) {
   DCHECK_LE(TOP, position);
   DCHECK_GE(LEFT, position);
@@ -130,16 +127,15 @@
   dict_value->SetString(kPositionKey, position_str);
   dict_value->SetInteger(kOffsetKey, layout.offset);
   dict_value->SetBoolean(kMirroredKey, layout.mirrored);
-  dict_value->SetBoolean(kDefaultUnifiedKey, layout.default_unified);
   dict_value->SetString(kPrimaryIdKey, base::Int64ToString(layout.primary_id));
   return true;
 }
 
 std::string DisplayLayout::ToString() const {
   const std::string position_str = GetStringFromPosition(position);
-  return base::StringPrintf("%s, %d%s%s", position_str.c_str(), offset,
-                            mirrored ? ", mirrored" : "",
-                            default_unified ? ", unified" : "");
+  return base::StringPrintf(
+      "%s, %d%s",
+      position_str.c_str(), offset, mirrored ? ", mirrored" : "");
 }
 
 // static
@@ -149,8 +145,6 @@
       kPositionKey, &DisplayLayout::position, &GetPositionFromString);
   converter->RegisterIntField(kOffsetKey, &DisplayLayout::offset);
   converter->RegisterBoolField(kMirroredKey, &DisplayLayout::mirrored);
-  converter->RegisterBoolField(kDefaultUnifiedKey,
-                               &DisplayLayout::default_unified);
   converter->RegisterCustomField<int64>(
       kPrimaryIdKey, &DisplayLayout::primary_id, &GetDisplayIdFromString);
 }