gtk: Grab the pointer when we grab focus for the source tab's widget. Fixes a crash where events were being sent to an unknown, unrealized widget.

BUG=18049
TEST=Quickly drag a tab down out of the tab strip.  The browser should not crash.
Review URL: http://codereview.chromium.org/160379

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@22084 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 8 insertions, 1 deletions

diff --git a/chrome/browser/gtk/tabs/tab_gtk.cc b/chrome/browser/gtk/tabs/tab_gtk.cc
index 90241100..a8a3ed6 100644
--- a/chrome/browser/gtk/tabs/tab_gtk.cc
+++ b/chrome/browser/gtk/tabs/tab_gtk.cc
@@ -217,6 +217,10 @@ void TabGtk::OnDragBegin(GtkWidget* widget, GdkDragContext* context,
 // static
 void TabGtk::OnDragEnd(GtkWidget* widget, GdkDragContext* context,
                        TabGtk* tab) {
+  // Release our grab on the pointer.
+  gdk_pointer_ungrab(GDK_CURRENT_TIME);
+  gtk_grab_remove(tab->widget());
+
   tab->dragging_ = false;
   // Notify the drag helper that we're done with any potential drag operations.
   // Clean up the drag helper, which is re-created on the next mouse press.
@@ -254,8 +258,11 @@ void TabGtk::DidProcessEvent(GdkEvent* event) {
       // limbo where the drag is still active, but we don't get any
       // motion-notify-event signals.  Adding the grab back doesn't keep the
       // drag alive, but it does get us out of this bind by finishing the drag.
-      if (delegate_->IsTabDetached(this))
+      if (delegate_->IsTabDetached(this)) {
+        gdk_pointer_grab(widget()->window, FALSE, GDK_POINTER_MOTION_HINT_MASK,
+                         NULL, NULL, GDK_CURRENT_TIME);
         gtk_grab_add(widget());
+      }
       break;
     default:
       break;