Change panel drag related methods to use mouse location in screen coordinates.

chrome/browser/ui/panels/panel_window_controller_cocoa.h

Index: chrome/browser/ui/panels/panel_window_controller_cocoa.h
diff --git a/chrome/browser/ui/panels/panel_window_controller_cocoa.h b/chrome/browser/ui/panels/panel_window_controller_cocoa.h
index 21fee91f6e4af309b10b1ffb04e520f912116775..11bcd5a49b5ff2f3f5f66aac30bf8dfd4ec6d379 100644
--- a/chrome/browser/ui/panels/panel_window_controller_cocoa.h
+++ b/chrome/browser/ui/panels/panel_window_controller_cocoa.h
@@ -98,11 +98,11 @@ class PanelBrowserWindowCocoa;
               animate:(BOOL)animate;
 
 // Used by PanelTitlebarViewCocoa when user rearranges the Panels by dragging.
+// |mouseLocation| is in screen coordinates.
 - (BOOL)isDraggable;
-- (void)startDrag;
+- (void)startDrag:(NSPoint)mouseLocation;
 - (void)endDrag:(BOOL)cancelled;
-- (void)dragWithDeltaX:(int)deltaX
-                deltaY:(int)deltaY;
+- (void)drag:(NSPoint)mouseLocation;
 
 // Accessor for titlebar view.
 - (PanelTitlebarViewCocoa*)titlebarView;