GTK: Try to position info bubbles onscreen.

chrome/browser/gtk/location_bar_view_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/location_bar_view_gtk.h"
 
 #include <string>
 
 #include "app/gfx/canvas_paint.h"
 #include "app/gfx/gtk_util.h"
@@ skipping 133 matching lines @@
                                                     profile_,
                                                     command_updater_,
                                                     popup_window_mode_,
                                                     bubble_positioner_));
   location_entry_->Init();
 
   hbox_.Own(gtk_hbox_new(FALSE, kInnerPadding));
   gtk_container_set_border_width(GTK_CONTAINER(hbox_.get()), kHboxBorder);
   // We will paint for the alignment, to paint the background and border.
   gtk_widget_set_app_paintable(hbox_.get(), TRUE);
-  // Have GTK double buffer around the expose signal.
-  gtk_widget_set_double_buffered(hbox_.get(), TRUE);
   // Redraw the whole location bar when it changes size (e.g., when toggling
   // the home button on/off.
   gtk_widget_set_redraw_on_allocate(hbox_.get(), TRUE);
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   security_lock_icon_image_ = gtk_image_new_from_pixbuf(
       rb.GetPixbufNamed(IDR_LOCK));
   gtk_widget_set_name(security_lock_icon_image_, "chrome-security-lock-icon");
   gtk_widget_hide(GTK_WIDGET(security_lock_icon_image_));
   security_warning_icon_image_ = gtk_image_new_from_pixbuf(
@@ skipping 657 matching lines @@
   const ExtensionActionState* state =
       contents->GetPageActionState(view->page_action_);
   if (!state || state->badge_text().empty())
     return FALSE;
 
   gfx::CanvasPaint canvas(event, false);
   gfx::Rect bounding_rect(widget->allocation);
   state->PaintBadge(&canvas, bounding_rect);
   return FALSE;
 }