[Mac] Do not show the fullscreen exit bubble while transitioning. Wait until the transition ends.

chrome/browser/ui/cocoa/browser_window_controller_private.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_private.h"
 
 #include <cmath>
 
 #include "base/command_line.h"
 #import "base/memory/scoped_nsobject.h"
@@ skipping 778 matching lines @@
   // mode, it needs to draw over the bookmark bar and part of the toolbar.
   [[infoBarContainerController_ view] removeFromSuperview];
   NSView* infoBarDest = [[self window] contentView];
   [infoBarDest addSubview:[infoBarContainerController_ view]
                positioned:fullscreen ? NSWindowBelow : NSWindowAbove
                relativeTo:fullscreen ? nil
                                      : [toolbarController_ view]];
 }
 
 - (void)showFullscreenExitBubbleIfNecessary {
+  // This method is called in response to
+  // |-updateFullscreenExitBubbleURL:bubbleType:|. If on Lion the system is
+  // transitioning, do not show the bubble because it will cause visual jank
+  // <http://crbug.com/130649>. This will be called again as part of
+  // |-windowDidEnterFullScreen:|, so arrange to do that work then instead.
+  if (enteringFullscreen_)
+    return;
+
   [presentationModeController_ ensureOverlayHiddenWithAnimation:NO delay:NO];
 
   if (fullscreenBubbleType_ == FEB_TYPE_NONE ||
       fullscreenBubbleType_ == FEB_TYPE_BROWSER_FULLSCREEN_EXIT_INSTRUCTION) {
     // Show no exit instruction bubble on Mac when in Browser Fullscreen.
     [self destroyFullscreenExitBubbleIfNecessary];
   } else {
     [fullscreenExitBubbleController_ closeImmediately];
     fullscreenExitBubbleController_.reset(
         [[FullscreenExitBubbleController alloc]
@@ skipping 105 matching lines @@
 - (void)disableBarVisibilityUpdates {
   // Early escape if there's nothing to do.
   if (!barVisibilityUpdatesEnabled_)
     return;
 
   barVisibilityUpdatesEnabled_ = NO;
   [presentationModeController_ cancelAnimationAndTimers];
 }
 
 @end  // @implementation BrowserWindowController(Private)