Give up on threaded animations for the Mac App Launcher NSWindow

chrome/browser/ui/app_list/app_list_service_mac.mm

 // Copyright 2013 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/app_list/app_list_service_mac.h"
 
 #include <ApplicationServices/ApplicationServices.h>
 #import <Cocoa/Cocoa.h>
 
 #include "base/bind.h"
@@ skipping 561 matching lines @@
   [animation_ setDelegate:self];
 
   if (closing) {
     [animation_ setAnimationCurve:NSAnimationEaseIn];
     window_.reset([window retain]);
   } else {
     [window setAlphaValue:0.0f];
     [animation_ setAnimationCurve:NSAnimationEaseOut];
     window_.reset();
   }
-  // Threaded animations are buggy on Snow Leopard. See http://crbug.com/335550.
-  // Note that in the non-threaded case, the animation won't start unless the
-  // UI runloop has spun up, so on <= Lion the animation will only animate if
-  // Chrome is already running.
-  if (base::mac::IsOSMountainLionOrLater())
-    [animation_ setAnimationBlockingMode:NSAnimationNonblockingThreaded];
-  else
-    [animation_ setAnimationBlockingMode:NSAnimationNonblocking];
+  // This once used a threaded animation, but AppKit would too often ignore
+  // -[NSView canDrawConcurrently:] and just redraw whole view hierarchies on
+  // the animation thread anyway, creating a minefield of race conditions.
+  // Non-threaded means the animation isn't as smooth and doesn't begin unless
+  // the UI runloop has spun up (after profile loading).
+  [animation_ setAnimationBlockingMode:NSAnimationNonblocking];
 
   [animation_ startAnimation];
 }
 
 - (void)cleanupOnUIThread {
   bool closing = [self isClosing];
   [window_ close];
   window_.reset();
   animation_.reset();
 
   if (closing)
     apps::AppShimHandler::MaybeTerminate();
 }
 
 - (void)animationDidEnd:(NSAnimation*)animation {
   content::BrowserThread::PostTask(
       content::BrowserThread::UI,
       FROM_HERE,
       base::Bind(&AppListServiceMac::WindowAnimationDidEnd,
                  base::Unretained(AppListServiceMac::GetInstance())));
 }
 
 @end