Revert "Caches the display names in MultiDisplayManager."

ash/display/multi_display_manager.h

Index: ash/display/multi_display_manager.h
diff --git a/ash/display/multi_display_manager.h b/ash/display/multi_display_manager.h
index 40b9f30db3d91f32104ff8617420587065a66f8f..79886465c15de9717f4164cfd655474363fd0a01 100644
--- a/ash/display/multi_display_manager.h
+++ b/ash/display/multi_display_manager.h
@@ -134,9 +134,6 @@ class ASH_EXPORT MultiDisplayManager : public aura::DisplayManager,
   // 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();
-
   // Update the display's id in the |display_list| to match the ones
   // stored in this display manager's |displays_|. This is used to
   // emulate display change behavior during the test byn creating the
@@ -155,9 +152,6 @@ class ASH_EXPORT MultiDisplayManager : public aura::DisplayManager,
   // The mapping from the display ID to its overscan insets.
   std::map<int64, gfx::Insets> overscan_mapping_;
 
-  // The cached display's name for the display ID.
-  std::map<int64, std::string> display_names_;
-
   DISALLOW_COPY_AND_ASSIGN(MultiDisplayManager);
 };