Support detaching/attaching panels via inter-strip drags.

chrome/browser/ui/panels/panel_strip.h

Index: chrome/browser/ui/panels/panel_strip.h
diff --git a/chrome/browser/ui/panels/panel_strip.h b/chrome/browser/ui/panels/panel_strip.h
index 7b0bced6fc2a6b29013fbc85f8db791ffa6d87dd..97028d65f442c93bbdc13372e900a559542f6dae 100644
--- a/chrome/browser/ui/panels/panel_strip.h
+++ b/chrome/browser/ui/panels/panel_strip.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_UI_PANELS_PANEL_STRIP_H_
 #pragma once
 
+#include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 
 class Panel;
@@ -34,6 +35,11 @@ class PanelStrip {
   // Adds |panel| to the collection of panels.
   virtual void AddPanel(Panel* panel) = 0;
 
+  // Adds |panel| to the collection of panels and positions it at or close to
+  // |position| that is in screen coordinates. It is up to the strip itself to
+  // decide the final position that the panel can be.
+  virtual void AddPanelAtPosition(Panel* panel, const gfx::Point& position) = 0;

[jennb, 2012/03/01 00:33:38]

Is the origin of the panel placed close to |position|? Could you explain more?

[jianli, 2012/03/02 22:42:43]

Renamed this method to AddDraggingPanel to mean it is only intended to be user
for adding dragging panel from another strip. Also updated the comment to remove
"close to position" since indeed we now place the panel at position.

+
   // Removes |panel| from the collection of panels. Invoked asynchronously
   // after a panel has been closed.
   // Returns |false| if the panel is not in the strip.