Change behaviour of the Alt-] and Alt-[ keys so that it cycles through SnapLeft/SnapRight to DockLe…

ash/wm/panels/panel_layout_manager.cc

Index: ash/wm/panels/panel_layout_manager.cc
diff --git a/ash/wm/panels/panel_layout_manager.cc b/ash/wm/panels/panel_layout_manager.cc
index bf69c2c06d349518f2533258192adcfcf38e40b6..c888567be330542301006e01c666e04285de3bc8 100644
--- a/ash/wm/panels/panel_layout_manager.cc
+++ b/ash/wm/panels/panel_layout_manager.cc
@@ -487,22 +487,27 @@ void PanelLayoutManager::OnWindowPropertyChanged(aura::Window* window,
 void PanelLayoutManager::OnPostWindowStateTypeChange(
     wm::WindowState* window_state,
     wm::WindowStateType old_type) {
+  aura::Window* window = window_state->window();
+  if (window_state->IsDocked()) {
+    wm::DockWindow(window);
+    return;
+  }
   // If the shelf is currently hidden then windows will not actually be shown
   // but the set to restore when the shelf becomes visible is updated.
   if (restore_windows_on_shelf_visible_) {
     if (window_state->IsMinimized()) {
-      MinimizePanel(window_state->window());
-      restore_windows_on_shelf_visible_->Remove(window_state->window());
+      MinimizePanel(window);
+      restore_windows_on_shelf_visible_->Remove(window);
     } else {
-      restore_windows_on_shelf_visible_->Add(window_state->window());
+      restore_windows_on_shelf_visible_->Add(window);
     }
     return;
   }
 
   if (window_state->IsMinimized())
-    MinimizePanel(window_state->window());
+    MinimizePanel(window);
   else
-    RestorePanel(window_state->window());
+    RestorePanel(window);
 }
 
 ////////////////////////////////////////////////////////////////////////////////