Refactor intra-strip panel drags by introducing PanelDragController.

chrome/browser/ui/panels/panel_browser_view.cc

Index: chrome/browser/ui/panels/panel_browser_view.cc
diff --git a/chrome/browser/ui/panels/panel_browser_view.cc b/chrome/browser/ui/panels/panel_browser_view.cc
index 598bade8afa1c61a668d5f7a87ace160328dfb49..8716cf517afb6484d5383f83164369362aacdff7 100644
--- a/chrome/browser/ui/panels/panel_browser_view.cc
+++ b/chrome/browser/ui/panels/panel_browser_view.cc
@@ -449,7 +449,7 @@ bool PanelBrowserView::OnTitlebarMouseDragged(const gfx::Point& location) {
   if (!mouse_pressed_)
     return false;
 
-  if (!panel_->draggable())
+  if (!panel_->manager()->CanDrag(panel_.get()))
     return true;
 
   gfx::Point last_mouse_location = mouse_location_;
@@ -472,7 +472,7 @@ bool PanelBrowserView::OnTitlebarMouseDragged(const gfx::Point& location) {
     mouse_dragging_state_ = DRAGGING_STARTED;
   }
   if (mouse_dragging_state_ == DRAGGING_STARTED)
-    panel_->manager()->Drag(delta_x);
+    panel_->manager()->Drag(delta_x, delta_y);
   return true;
 }