Do not block all task manager tree view mouse release events....

chrome/browser/gtk/task_manager_gtk.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/gtk/task_manager_gtk.h"
 
 #include <gdk/gdkkeysyms.h>
 
 #include <vector>
 
@@ skipping 323 matching lines @@
                                  GTK_POLICY_NEVER, GTK_POLICY_NEVER);
 
   gtk_container_add(GTK_CONTAINER(GTK_DIALOG(dialog_)->vbox), scrolled);
 
   CreateTaskManagerTreeview();
   gtk_tree_view_set_headers_clickable(GTK_TREE_VIEW(treeview_), TRUE);
   gtk_tree_view_set_grid_lines(GTK_TREE_VIEW(treeview_),
                                GTK_TREE_VIEW_GRID_LINES_HORIZONTAL);
   g_signal_connect(G_OBJECT(treeview_), "button-press-event",
                    G_CALLBACK(OnButtonPressEvent), this);
-  g_signal_connect(G_OBJECT(treeview_), "button-release-event",
-                   G_CALLBACK(OnButtonReleaseEvent), this);
   gtk_widget_add_events(treeview_,
                         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK);
 
   // Hide some columns by default
   TreeViewColumnSetVisible(treeview_, kTaskManagerSharedMem, false);
   TreeViewColumnSetVisible(treeview_, kTaskManagerPrivateMem, false);
   TreeViewColumnSetVisible(treeview_, kTaskManagerProcessID, false);
   TreeViewColumnSetVisible(treeview_, kTaskManagerGoatsTeleported, false);
 
   // |selection| is owned by |treeview_|.
@@ skipping 190 matching lines @@
   if (event->type == GDK_2BUTTON_PRESS)
     task_manager->ActivateFocusedTab();
 
   return FALSE;
 }
 
 // static
 gboolean TaskManagerGtk::OnButtonReleaseEvent(GtkWidget* widget,
                                               GdkEventButton* event,
                                               TaskManagerGtk* task_manager) {
-  // We don't want to open the context menu in the treeview.
-  if (widget == task_manager->treeview_)
-    return TRUE;
+  if (gtk_util::WidgetContainsCursor(task_manager->treeview_))
+    return FALSE;
 
   if (event->button == 3)
     task_manager->ShowContextMenu();
 
   return FALSE;
 }
 
 // static
 gboolean TaskManagerGtk::OnGtkAccelerator(GtkAccelGroup* accel_group,
                                           GObject* acceleratable,
                                           guint keyval,
                                           GdkModifierType modifier,
                                           TaskManagerGtk* task_manager) {
   if (keyval == GDK_w && modifier == GDK_CONTROL_MASK) {
     // The GTK_RESPONSE_DELETE_EVENT response must be sent before the widget
     // is destroyed.  The deleted object will receive gtk signals otherwise.
     gtk_dialog_response(GTK_DIALOG(task_manager->dialog_),
                         GTK_RESPONSE_DELETE_EVENT);
     gtk_widget_destroy(task_manager->dialog_);
   }
 
   return TRUE;
 }