Use active window if on current workspace for fullscreen mode.

ash/wm/mru_window_tracker.cc

Index: ash/wm/mru_window_tracker.cc
diff --git a/ash/wm/mru_window_tracker.cc b/ash/wm/mru_window_tracker.cc
index 0a63e32a47a26c84c13269cf34344ba895f2d643..a5769ec05a1fcf741f00646787fa375cc2848f49 100644
--- a/ash/wm/mru_window_tracker.cc
+++ b/ash/wm/mru_window_tracker.cc
@@ -181,6 +181,29 @@ void MruWindowTracker::SetIgnoreActivations(bool ignore) {
     SetActiveWindow(wm::GetActiveWindow());
 }
 
+const aura::Window* MruWindowTracker::GetMruWindowInRoot(
+    const aura::Window* root_window) {
+  if (ignore_window_activations_) {
+    // While cycling windows, the activated windows list will not track window
+    // activations so as to correctly maintain the most recently used window
+    // order. Despite this, we should still treat the currently active window as
+    // most recently used for the purpose of window management.
+    aura::Window* active_window = wm::GetActiveWindow();
+    if (active_window && active_window->GetRootWindow() == root_window &&
+        IsSwitchableContainer(active_window->parent())) {
+      return active_window;
+    }
+  }
+
+  for (std::list<aura::Window*>::const_iterator iter = mru_windows_.begin();
+       iter != mru_windows_.end(); ++iter) {
+    if ((*iter)->GetRootWindow() == root_window &&
+        IsSwitchableContainer((*iter)->parent()))
+      return *iter;
+  }
+  return NULL;
+}
+
 //////////////////////////////////////////////////////////////////////////////
 // MruWindowTracker, private: