Make GTK Panels ignore mouse/keyboard events after drag is ended until mouse is released.

chrome/browser/ui/panels/panel_browser_window_gtk.cc

Index: chrome/browser/ui/panels/panel_browser_window_gtk.cc
diff --git a/chrome/browser/ui/panels/panel_browser_window_gtk.cc b/chrome/browser/ui/panels/panel_browser_window_gtk.cc
index d6461451f22d11be0b80bf688d5f647cd6c9b831..3de6d467c15df270946815f54fb1e28b81ff0a69 100644
--- a/chrome/browser/ui/panels/panel_browser_window_gtk.cc
+++ b/chrome/browser/ui/panels/panel_browser_window_gtk.cc
@@ -638,15 +638,14 @@ void NativePanelTestingGtk::DragTitlebar(const gfx::Point& mouse_location) {
 void NativePanelTestingGtk::CancelDragTitlebar() {
   if (!panel_browser_window_gtk_->drag_helper_.get())
     return;
-
-  panel_browser_window_gtk_->drag_helper_->EndDrag(true);
+  panel_browser_window_gtk_->drag_helper_->OnGrabBrokenEvent(NULL, NULL);
+  MessageLoopForUI::current()->RunAllPending();
 }
 
 void NativePanelTestingGtk::FinishDragTitlebar() {
   if (!panel_browser_window_gtk_->drag_helper_.get())
     return;
-
-  panel_browser_window_gtk_->drag_helper_->EndDrag(false);
+  ReleaseMouseButtonTitlebar(panel::NO_MODIFIER);
 }
 
 bool NativePanelTestingGtk::VerifyDrawingAttention() const {