Animate the fullscreen exit bubble's opacity instead of its bounds when in immersive fullscreen

chrome/browser/ui/gtk/fullscreen_exit_bubble_gtk.cc

 // Copyright (c) 2012 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/ui/gtk/fullscreen_exit_bubble_gtk.h"
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/gtk/gtk_chrome_link_button.h"
 #include "chrome/browser/ui/gtk/gtk_theme_service.h"
@@ skipping 207 matching lines @@
 }
 
 void FullscreenExitBubbleGtk::Show() {
   slide_widget_->Open();
 }
 
 bool FullscreenExitBubbleGtk::IsAnimating() {
   return slide_widget_->IsAnimating();
 }
 
+bool FullscreenExitBubbleGtk::CanMouseTriggerSlideIn() const {
+  return true;
+}
+
 void FullscreenExitBubbleGtk::StartWatchingMouseIfNecessary() {
   if (!fullscreen_bubble::ShowButtonsForType(bubble_type_))
     StartWatchingMouse();
 }
 
 void FullscreenExitBubbleGtk::OnSetFloatingPosition(
     GtkWidget* floating_container,
     GtkAllocation* allocation) {
   GtkRequisition bubble_size;
   gtk_widget_size_request(widget(), &bubble_size);
@@ skipping 26 matching lines @@
 void FullscreenExitBubbleGtk::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(type, chrome::NOTIFICATION_BROWSER_THEME_CHANGED);
   if (theme_service_->UsingNativeTheme())
     gtk_widget_modify_bg(bubble_, GTK_STATE_NORMAL, NULL);
   else
     gtk_widget_modify_bg(bubble_, GTK_STATE_NORMAL, &kBackgroundColor);
 }