[Mac] Refactor Immersive Fullscreen Logic

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_toolbar_controller.h"
 #include "ui/base/cocoa/appkit_utils.h"
@@ skipping 90 matching lines @@
   if (!trackingArea_)
     return;
 
   DCHECK(contentView_);
   [contentView_ removeTrackingArea:trackingArea_];
   trackingArea_.reset();
   contentView_ = nil;
 }
 
 - (BOOL)mouseInsideTrackingArea {
-  if (!trackingArea_)
-    return NO;
-
-  NSPoint mouseLoc = [[contentView_ window] mouseLocationOutsideOfEventStream];
-  NSPoint mousePos = [contentView_ convertPoint:mouseLoc fromView:nil];
-  return NSMouseInRect(mousePos, trackingAreaFrame_, [contentView_ isFlipped]);
+  return [trackingArea_ mouseInsideTrackingAreaForView:contentView_];
 }
 
 - (void)mouseEntered:(NSEvent*)event {
   // Empty implementation. Required for CrTrackingArea.
 }
 
 - (void)mouseExited:(NSEvent*)event {
   DCHECK_EQ([event trackingArea], trackingArea_.get());
 
   animationController_->AnimateToolbarOutIfPossible();
 
   [owner_ updateToolbar];
   [self removeTrackingArea];
 }
 
 @end