Do not show auto-hidden shelf when dragging a window

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 4ed9a1df7230add4d26cfe61e7f7828bd220b76a..fc942cb414a5c11af78cc04a6cb4782b69f13e1f 100644
--- a/ash/wm/mru_window_tracker.cc
+++ b/ash/wm/mru_window_tracker.cc
@@ -10,6 +10,7 @@
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/wm/window_cycle_list.h"
+#include "ash/wm/window_state.h"
 #include "ash/wm/window_util.h"
 #include "ash/wm/workspace_controller.h"
 #include "ui/aura/client/activation_client.h"
@@ -31,6 +32,19 @@ void AddTrackedWindows(aura::Window* root,
   windows->insert(windows->end(), children.begin(), children.end());
 }
 
+// Adds windows being dragged in the docked container to |windows| list.
+void AddDraggedWindows(aura::Window* root,
+                       MruWindowTracker::WindowList* windows) {
+  aura::Window* container = Shell::GetContainer(
+      root, internal::kShellWindowId_DockedContainer);
+  const MruWindowTracker::WindowList& children = container->children();
+  for (MruWindowTracker::WindowList::const_iterator iter = children.begin();
+       iter != children.end(); ++iter) {
+    if (wm::GetWindowState(*iter)->is_dragged())
+      windows->insert(windows->end(), *iter);
+  }
+}
+
 // Returns true if |window| is a container whose windows can be cycled to.
 bool IsSwitchableContainer(aura::Window* window) {
   if (!window)
@@ -73,6 +87,10 @@ MruWindowTracker::WindowList BuildWindowListInternal(
   for (size_t i = 0; i < kSwitchableWindowContainerIdsLength; ++i)
     AddTrackedWindows(active_root, kSwitchableWindowContainerIds[i], &windows);
 
+  // Dragged windows are temporarily parented in docked container. Include them
+  // in the in tracked list.
+  AddDraggedWindows(active_root, &windows);
+
   // Removes unfocusable windows.
   MruWindowTracker::WindowList::iterator last =
       std::remove_if(