Refactor intra-strip panel drags by introducing PanelDragController.

chrome/browser/ui/panels/panel.h

Index: chrome/browser/ui/panels/panel.h
diff --git a/chrome/browser/ui/panels/panel.h b/chrome/browser/ui/panels/panel.h
index 7ef49187ed2ff620d3c441a1a3eb2ba1fb802455..0b63e4f55158ba7c7716df92dd8bc7e35f9dfdbe 100644
--- a/chrome/browser/ui/panels/panel.h
+++ b/chrome/browser/ui/panels/panel.h
@@ -233,8 +233,7 @@ class Panel : public BrowserWindow,
   const gfx::Size& max_size() const { return max_size_; }
   bool auto_resizable() const { return auto_resizable_; }
 
-  bool draggable() const { return draggable_; }
-  void set_draggable(bool can_drag) { draggable_ = can_drag; }
+  bool draggable() const;
 
   // The restored size is the size of the panel when it is expanded.
   gfx::Size restored_size() const { return restored_size_; }
@@ -316,9 +315,6 @@ class Panel : public BrowserWindow,
   // True if this panel auto resizes based on content.
   bool auto_resizable_;
 
-  // True if this panel can be dragged.
-  bool draggable_;
-
   // Platform specifc implementation for panels.  It'd be one of
   // PanelBrowserWindowGtk/PanelBrowserView/PanelBrowserWindowCocoa.
   NativePanel* native_panel_;  // Weak, owns us.