Enable user resizing for docked Panels (GTK and Mac).

chrome/browser/ui/panels/panel_manager.cc

Index: chrome/browser/ui/panels/panel_manager.cc
diff --git a/chrome/browser/ui/panels/panel_manager.cc b/chrome/browser/ui/panels/panel_manager.cc
index 07dd99997b5e67f42e5269fba514d0b69cae186a..8bcb41cd980b202cbee090460cee57d968fd084e 100644
--- a/chrome/browser/ui/panels/panel_manager.cc
+++ b/chrome/browser/ui/panels/panel_manager.cc
@@ -187,7 +187,7 @@ void PanelManager::EndDragging(bool cancelled) {
 void PanelManager::StartResizingByMouse(Panel* panel,
     const gfx::Point& mouse_location,
     panel::ResizingSides sides) {
-   if (panel->panel_strip() && panel->panel_strip()->CanResizePanel(panel) &&
+  if (panel->CanResizeByMouse() != panel::NOT_RESIZABLE &&
       sides != panel::RESIZE_NONE)
     resize_controller_->StartResizing(panel, mouse_location, sides);
 }
@@ -239,9 +239,9 @@ void PanelManager::ResizePanel(Panel* panel, const gfx::Size& new_size) {
 
 void PanelManager::OnPanelResizedByMouse(Panel* panel,
                                          const gfx::Rect& new_bounds) {
+  panel->set_restored_size(new_bounds.size());
   panel->panel_strip()->OnPanelResizedByMouse(panel, new_bounds);
   panel->SetAutoResizable(false);
-
 }
 
 void PanelManager::MovePanelToStrip(