Stick windows to sides of workspaces

ash/wm/panels/panel_window_resizer.cc

Index: ash/wm/panels/panel_window_resizer.cc
diff --git a/ash/wm/panels/panel_window_resizer.cc b/ash/wm/panels/panel_window_resizer.cc
index 947cf90931b0cbbbd2a814f8f926d56bf4329b47..c9c1c7d50476dc1bbcc5fd6e42c123df8eaefe7b 100644
--- a/ash/wm/panels/panel_window_resizer.cc
+++ b/ash/wm/panels/panel_window_resizer.cc
@@ -57,6 +57,8 @@ PanelWindowResizer::Create(WindowResizer* next_window_resizer,
 }
 
 void PanelWindowResizer::Drag(const gfx::Point& location, int event_flags) {
+  last_mouse_location_ = location;
+  wm::ConvertPointToScreen(GetTarget()->parent(), &last_mouse_location_);
   bool destroyed = false;
   if (!did_move_or_resize_) {
     did_move_or_resize_ = true;
@@ -134,6 +136,7 @@ PanelWindowResizer::PanelWindowResizer(WindowResizer* next_window_resizer,
       should_attach_(was_attached_),
       destroyed_(NULL) {
   DCHECK(details_.is_resizable);
+  root_window_ = details.window->GetRootWindow();
   panel_container_ = Shell::GetContainer(
       details.window->GetRootWindow(),
       internal::kShellWindowId_PanelContainer);
@@ -188,7 +191,7 @@ void PanelWindowResizer::StartedDragging() {
   // attaching it so that it does not get repositioned.
   if (panel_container_)
     GetPanelLayoutManager(panel_container_)->StartDragging(GetTarget());
-  if (!was_attached_) {
+  if (!was_attached_ && !IsWindowDocked(GetTarget())) {
     // Attach the panel while dragging placing it in front of other panels.
     GetTarget()->SetProperty(internal::kContinueDragAfterReparent, true);
     GetTarget()->SetProperty(internal::kPanelAttachedKey, true);
@@ -204,9 +207,9 @@ void PanelWindowResizer::FinishDragging() {
   if (GetTarget()->GetProperty(internal::kPanelAttachedKey) !=
       should_attach_) {
     GetTarget()->SetProperty(internal::kPanelAttachedKey, should_attach_);
-    GetTarget()->SetDefaultParentByRootWindow(
-        GetTarget()->GetRootWindow(),
-        GetTarget()->GetBoundsInScreen());
+    gfx::Rect near_last_mouse_location(last_mouse_location_, gfx::Size());
+    GetTarget()->SetDefaultParentByRootWindow(root_window_,
+                                              near_last_mouse_location);
   }
   if (panel_container_)
     GetPanelLayoutManager(panel_container_)->FinishDragging();