[Mac] Fullscreen Toolbar Fixes

chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_mouse_tracker.mm

 // Copyright 2016 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.
 
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_mouse_tracker.h"
 
 #include "chrome/browser/ui/cocoa/browser_window_controller.h"
 #include "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_animation_controller.h"
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_controller.h"
 #include "ui/base/cocoa/appkit_utils.h"
 #import "ui/base/cocoa/tracking_area.h"
 
 namespace {
 
 // Additional height threshold added at the toolbar's bottom. This is to mimic
 // threshold the mouse position needs to be at before the menubar automatically
 // hides.
-const CGFloat kTrackingAreaAdditionalThreshold = 20;
+const CGFloat kTrackingAreaAdditionalThreshold = 50;
 
 }  // namespace
 
 @interface FullscreenToolbarMouseTracker () {
   // The frame for the tracking area. The value is the toolbar's frame with
   // additional height added at the bottom.
   NSRect trackingAreaFrame_;
 
   // The tracking area associated with the toolbar. This tracking area is used
   // to keep the toolbar active if the menubar had animated out but the mouse
@@ skipping 89 matching lines @@
 - (void)mouseExited:(NSEvent*)event {
   DCHECK_EQ([event trackingArea], trackingArea_.get());
 
   animationController_->AnimateToolbarOutIfPossible();
 
   [owner_ updateToolbarLayout];
   [self removeTrackingArea];
 }
 
 @end