MD Settings: Display: Add unified desktop control and modify api

extensions/browser/api/system_display/display_info_provider.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef EXTENSIONS_BROWSER_API_SYSTEM_DISPLAY_DISPLAY_INFO_PROVIDER_H_
 #define EXTENSIONS_BROWSER_API_SYSTEM_DISPLAY_DISPLAY_INFO_PROVIDER_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 42 matching lines @@
                        const api::system_display::DisplayProperties& info,
                        std::string* error) = 0;
 
   // Implements SetDisplayLayout methods. See system_display.idl. Returns
   // false if the layout input is invalid.
   virtual bool SetDisplayLayout(const DisplayLayoutList& layouts);
 
   // Enables the unified desktop feature.
   virtual void EnableUnifiedDesktop(bool enable);
 
-  // Gets display information.
-  virtual DisplayUnitInfoList GetAllDisplaysInfo();
+  // Returns a list of information for all displays. If |single_unified| is
+  // true, when in unified mode a single display will be returned representing
+  // the single unified desktop.
+  virtual DisplayUnitInfoList GetAllDisplaysInfo(bool single_unified);
 
   // Gets display layout information.
   virtual DisplayLayoutList GetDisplayLayout();
 
   // Implements overscan calbiration methods. See system_display.idl. These
   // return false if |id| is invalid.
   virtual bool OverscanCalibrationStart(const std::string& id);
   virtual bool OverscanCalibrationAdjust(
       const std::string& id,
       const api::system_display::Insets& delta);
@@ skipping 33 matching lines @@
   virtual void UpdateDisplayUnitInfoForPlatform(
       const display::Display& display,
       api::system_display::DisplayUnitInfo* unit) = 0;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayInfoProvider);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_SYSTEM_DISPLAY_DISPLAY_INFO_PROVIDER_H_