[Cleanup] Factor out layout store code from DisplayController

ash/display/display_layout_store.h

Index: ash/display/display_layout_store.h
diff --git a/ash/display/display_layout_store.h b/ash/display/display_layout_store.h
new file mode 100644
index 0000000000000000000000000000000000000000..cb5b109b588d06b2dfcc48d9c64c058739af717d
--- /dev/null
+++ b/ash/display/display_layout_store.h
@@ -0,0 +1,69 @@
+// Copyright (c) 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 ASH_DISPLAY_DISPLAY_LAYOUT_STORE_H_
+#define ASH_DISPLAY_DISPLAY_LAYOUT_STORE_H_
+
+#include <map>
+
+#include "ash/ash_export.h"
+#include "ash/display/display_layout.h"
+
+namespace ash {
+namespace internal {
+
+class ASH_EXPORT DisplayLayoutStore {
+ public:
+  DisplayLayoutStore();
+  ~DisplayLayoutStore();
+
+  const DisplayLayout& default_display_layout() const {
+    return default_display_layout_;
+  }
+  void SetDefaultDisplayLayout(const DisplayLayout& layout);
+
+  // Registeres the display layout info for the specified display(s).
+  void RegisterLayoutForDisplayIdPair(int64 id1,
+                                      int64 id2,
+                                      const DisplayLayout& layout);
+
+  // If no layout is registered, it creatas new layout using
+  // |default_display_layout_|.
+  DisplayLayout GetRegisteredDisplayLayout(const DisplayIdPair& pair);
+
+  // Returns the display layout for the display id pair
+  // with display swapping applied.  That is, this returns
+  // flipped layout if the displays are swapped.
+  DisplayLayout ComputeDisplayLayoutForDisplayIdPair(
+      const DisplayIdPair& display_pair);
+
+  // Update the mirrored flag in the display layout for
+  // |display_pair|.  This creates new display layout if no layout is
+  // registered for |display_pair|.
+  void UpdateMirrorStatus(const DisplayIdPair& display_pair,
+                          bool mirrored);
+
+  // Update the |primary_id| in the display layout for
+  // |display_pair|.  This creates new display layout if no layout is
+  // registered for |display_pair|.
+  void UpdatePrimaryDisplayId(const DisplayIdPair& display_pair,
+                              int64 display_id);
+
+ private:
+  // Creates new layout for display pair from |default_display_layout_|.
+  DisplayLayout CreateDisplayLayout(const DisplayIdPair& display_pair);
+
+  // The default display layout.
+  DisplayLayout default_display_layout_;
+
+  // Display layout per pair of devices.
+  std::map<DisplayIdPair, DisplayLayout> paired_layouts_;
+
+  DISALLOW_COPY_AND_ASSIGN(DisplayLayoutStore);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_DISPLAY_DISPLAY_LAYOUT_STORE_H_