Prevents panels attached to shelf from docking

ash/wm/workspace/multi_window_resize_controller.cc

Index: ash/wm/workspace/multi_window_resize_controller.cc
diff --git a/ash/wm/workspace/multi_window_resize_controller.cc b/ash/wm/workspace/multi_window_resize_controller.cc
index 573824e6bc332f7e72b43d6e9519ccdc42ba0faa..afc66fdb117f2833c70b4799728f5b035922bc2e 100644
--- a/ash/wm/workspace/multi_window_resize_controller.cc
+++ b/ash/wm/workspace/multi_window_resize_controller.cc
@@ -433,12 +433,14 @@ void MultiWindowResizeController::StartResize(
     windows.push_back(windows_.other_windows[i]);
   }
   int component = windows_.direction == LEFT_RIGHT ? HTRIGHT : HTBOTTOM;
-  window_resizer_.reset(WorkspaceWindowResizer::Create(
+  scoped_ptr<DragDetails> details(new DragDetails(
       windows_.window1,
       location_in_parent,
       component,
-      aura::client::WINDOW_MOVE_SOURCE_MOUSE,
-      windows));
+      aura::client::WINDOW_MOVE_SOURCE_MOUSE));
+  wm::WindowState* window_state = wm::GetWindowState(windows_.window1);
+  window_state->set_drag_details(details.release());
+  window_resizer_.reset(WorkspaceWindowResizer::Create(window_state, windows));
 }
 
 void MultiWindowResizeController::Resize(const gfx::Point& location_in_screen,
@@ -460,6 +462,7 @@ void MultiWindowResizeController::Resize(const gfx::Point& location_in_screen,
 
 void MultiWindowResizeController::CompleteResize() {
   window_resizer_->CompleteDrag();
+  wm::GetWindowState(window_resizer_->GetTarget())->set_drag_details(NULL);
   window_resizer_.reset();
 
   // Mouse may still be over resizer, if not hide.
@@ -480,6 +483,7 @@ void MultiWindowResizeController::CancelResize() {
   if (!window_resizer_)
     return;  // Happens if window was destroyed and we nuked the WindowResizer.
   window_resizer_->RevertDrag();
+  wm::GetWindowState(window_resizer_->GetTarget())->set_drag_details(NULL);
   window_resizer_.reset();
   Hide();
 }