athena: Add a test for split-view controller.

athena/wm/split_view_controller.h

Index: athena/wm/split_view_controller.h
diff --git a/athena/wm/split_view_controller.h b/athena/wm/split_view_controller.h
index d7dc20c0328f821e755a97051add5040b56fdf7b..2e5d0ce0490abff4920344ffa4cf9ed8f930d2f1 100644
--- a/athena/wm/split_view_controller.h
+++ b/athena/wm/split_view_controller.h
@@ -5,6 +5,7 @@
 #ifndef ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_
 #define ATHENA_WM_SPLIT_VIEW_CONTROLLER_H_
 
+#include "athena/athena_export.h"
 #include "athena/wm/bezel_controller.h"
 #include "athena/wm/public/window_manager_observer.h"
 #include "athena/wm/window_overview_mode.h"
@@ -22,8 +23,9 @@ class WindowOverviewModeDelegate;
 
 // Responsible for entering split view mode, exiting from split view mode, and
 // laying out the windows in split view mode.
-class SplitViewController : public BezelController::ScrollDelegate,
-                            public WindowManagerObserver {
+class ATHENA_EXPORT SplitViewController
+    : public BezelController::ScrollDelegate,
+    public WindowManagerObserver {
  public:
   SplitViewController(aura::Window* container,
                       WindowListProvider* window_list_provider,
@@ -38,6 +40,9 @@ class SplitViewController : public BezelController::ScrollDelegate,
   // |left| nor |right|) is selected instead.
   void ActivateSplitMode(aura::Window* left, aura::Window* right);
 
+  aura::Window* left_window() { return left_window_; }
+  aura::Window* right_window() { return right_window_; }
+
  private:
   enum State {
     // Split View mode is not active. |left_window_| and |right_window| are
@@ -81,8 +86,9 @@ class SplitViewController : public BezelController::ScrollDelegate,
 
   aura::Window* container_;
 
-  // Window Manager which owns this SplitViewController.
-  // Must be non NULL for the duration of the lifetime.
+  // Window Manager which owns this SplitViewController. The window manager must
+  // be alive for the duration of the lifetime of the SplitViewController.
+  // Can be NULL (in tests).

[oshima, 2014/08/14 23:09:44]

Can you create Screen/WindowManager for now? (I'd like to avoid adding if non
null for testing)

I'll update the test base to initialize (like ash's test) so that you don't have
to do this.

[sadrul, 2014/08/15 00:20:14]

I have removed the need for the WindowManager from SVC in
https://codereview.chromium.org/470083004/. If that goes through, this wouldn't
be an issue anymore.

   WindowManager* window_manager_;
 
   // Provider of the list of windows to cycle through. Not owned.