Show no exit instruction on Mac when in Browser Fullscreen.

chrome/browser/ui/cocoa/browser_window_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 
 #include <cmath>
 #include <numeric>
 
 #include "base/command_line.h"
@@ skipping 1967 matching lines @@
 
 - (void)exitFullscreen {
   // url: and bubbleType: are ignored when leaving fullscreen.
   [self setFullscreen:NO url:GURL() bubbleType:FEB_TYPE_NONE];
 }
 
 - (void)updateFullscreenExitBubbleURL:(const GURL&)url
                            bubbleType:(FullscreenExitBubbleType)bubbleType {
   fullscreenUrl_ = url;
   fullscreenBubbleType_ = bubbleType;
-  if (bubbleType == FEB_TYPE_NONE) {
+  if (bubbleType == FEB_TYPE_NONE ||
+      bubbleType == FEB_TYPE_BROWSER_FULLSCREEN_EXIT_INSTRUCTION) {
+    // Show no exit instruction bubble on Mac when in Browser Fullscreen.
     [self destroyFullscreenExitBubbleIfNecessary];
   } else {
     if (!fullscreenExitBubbleController_.get()) {
       [self showFullscreenExitBubbleIfNecessary];
     }
     [fullscreenExitBubbleController_.get() updateURL:url bubbleType:bubbleType];
   }
 }
 
 - (BOOL)isFullscreen {
@@ skipping 219 matching lines @@
 
 - (BOOL)supportsBookmarkBar {
   return [self supportsWindowFeature:Browser::FEATURE_BOOKMARKBAR];
 }
 
 - (BOOL)isTabbedWindow {
   return browser_->is_type_tabbed();
 }
 
 @end  // @implementation BrowserWindowController(WindowType)