Allow storing display preferences per device.

ash/display/display_controller.h

Index: ash/display/display_controller.h
diff --git a/ash/display/display_controller.h b/ash/display/display_controller.h
index 41aaeb19b5eaf7745cbcf44568141d10bda2372c..9c41525e96860f5e0c3ce4b0c896906792afade7 100644
--- a/ash/display/display_controller.h
+++ b/ash/display/display_controller.h
@@ -20,22 +20,41 @@ class Display;
 class RootWindow;
 }
 
+namespace base {
+class DictionaryValue;
+class Value;
+template <typename T> class JSONValueConverter;
+}
+
 namespace ash {
 namespace internal {
 class RootWindowController;
 
-// DisplayController owns and maintains RootWindows for each attached
-// display, keeping them in sync with display configuration changes.
-class ASH_EXPORT DisplayController : public aura::DisplayObserver {
- public:
+struct ASH_EXPORT DisplayLayout {
   // Layout options where the secondary display should be positioned.
-  enum SecondaryDisplayLayout {
+  enum Position {
     TOP,
     RIGHT,
     BOTTOM,
     LEFT
   };
+  Position position;
+
+  // The offset of the position of the secondary display.  The offset is
+  // based on the top/left edge of the primary display.
+  int offset;
 
+  DisplayLayout();
+  DisplayLayout(Position position, int offset);
+  static void RegisterJSONConverter(
+      base::JSONValueConverter<DisplayLayout>* converter);
+  bool ConvertToValue(base::DictionaryValue* value);
+};
+
+// DisplayController owns and maintains RootWindows for each attached
+// display, keeping them in sync with display configuration changes.
+class ASH_EXPORT DisplayController : public aura::DisplayObserver {
+ public:
   DisplayController();
   virtual ~DisplayController();
 
@@ -64,15 +83,16 @@ class ASH_EXPORT DisplayController : public aura::DisplayObserver {
   // mode, this return a RootWindowController for the primary root window only.
   std::vector<internal::RootWindowController*> GetAllRootWindowControllers();
 
-  SecondaryDisplayLayout secondary_display_layout() const {
-    return secondary_display_layout_;
+  const DisplayLayout& default_display_layout() const {
+    return default_display_layout_;
   }
-  void SetSecondaryDisplayLayout(SecondaryDisplayLayout layout);
+  void SetDefaultDisplayLayout(const DisplayLayout& layout);
 
-  int secondary_display_offset() const {
-    return secondary_display_offset_;
-  }
-  void SetSecondaryDisplayOffset(int offset);
+  // Sets/gets the display layout for the specified display name.  Getter
+  // returns the default value in case it doesn't have its own layout yet.
+  void SetLayoutForDisplayName(const std::string& name,
+                               const DisplayLayout& layout);
+  const DisplayLayout& GetLayoutForDisplayName(const std::string& name);
 
   void set_dont_warp_mouse(bool dont_warp_mouse) {
     dont_warp_mouse_ = dont_warp_mouse;
@@ -110,11 +130,11 @@ class ASH_EXPORT DisplayController : public aura::DisplayObserver {
   // The mapping from display ID to its root window.
   std::map<int64, aura::RootWindow*> root_windows_;
 
-  SecondaryDisplayLayout secondary_display_layout_;
+  // The default display layout.
+  DisplayLayout default_display_layout_;
 
-  // The offset of the position of the secondary display.  The offset is
-  // based on the top/left edge of the primary display.
-  int secondary_display_offset_;
+  // Per-device display layout.
+  std::map<std::string, DisplayLayout> secondary_layouts_;
 
   // If true, the mouse pointer can't move from one display to another.
   bool dont_warp_mouse_;