Separate ash::test::DisplayManagerTestApi from ash

ash/display/display_manager.h

Index: ash/display/display_manager.h
diff --git a/ash/display/display_manager.h b/ash/display/display_manager.h
index dd684cf053bd11d62b09c9ef6ddbde1b4eada535..9b2c17de7ae99c387e0ad580c251f60d709ae422 100644
--- a/ash/display/display_manager.h
+++ b/ash/display/display_manager.h
@@ -43,7 +43,6 @@ namespace ash {
 using DisplayInfoList = std::vector<display::ManagedDisplayInfo>;
 
 namespace test {
-class AshTestBase;
 class DisplayManagerTestApi;
 }
 
@@ -348,15 +347,11 @@ class ASH_EXPORT DisplayManager
   void AddObserver(display::DisplayObserver* observer);
   void RemoveObserver(display::DisplayObserver* observer);
 
+  // Returns a display::Display object for a secondary display if it exists
+  // or returns invalid display if there is no secondary display.
+  const display::Display& GetSecondaryDisplay() const;

[oshima, 2016/10/04 00:47:16]

just fyi: "swap display" is a legacy feature we added long time ago before
adding multi display, to allow switching which display to use. We probably
should remove it at some point.

[rjkroege, 2016/10/05 00:21:45]

I added a TODO.

+
  private:
-  FRIEND_TEST_ALL_PREFIXES(ExtendedDesktopTest, ConvertPoint);
-  FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, TestNativeDisplaysChanged);
-  FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest,
-                           NativeDisplaysChangedAfterPrimaryChange);
-  FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, AutomaticOverscanInsets);
-  FRIEND_TEST_ALL_PREFIXES(DisplayManagerTest, Rotate);
-  friend class DisplayManagerTest;
-  friend class test::AshTestBase;
   friend class test::DisplayManagerTestApi;
 
   bool software_mirroring_enabled() const {