[Mac] Fullscreen Toolbar Janky Animation Fix

chrome/browser/ui/cocoa/fullscreen/fullscreen_menubar_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_menubar_tracker.h"
 
 #include <Carbon/Carbon.h>
 
+#include "base/mac/mac_util.h"
 #include "base/macros.h"
 #import "chrome/browser/ui/cocoa/browser_window_controller.h"
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_controller.h"
+#import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_visibility_lock_controller.h"
 #include "ui/base/cocoa/appkit_utils.h"
 
 namespace {
 
 // The event kind value for a undocumented menubar show/hide Carbon event.
 const CGFloat kMenuBarRevealEventKind = 2004;
 
 OSStatus MenuBarRevealHandler(EventHandlerCallRef handler,
                               EventRef event,
                               void* context) {
@@ skipping 107 matching lines @@
 
   if (ui::IsCGFloatEqual(progress, 1.0))
     state_ = FullscreenMenubarState::SHOWN;
   else if (ui::IsCGFloatEqual(progress, 0.0))
     state_ = FullscreenMenubarState::HIDDEN;
   else if (progress < menubarFraction_)
     state_ = FullscreenMenubarState::HIDING;
   else if (progress > menubarFraction_)
     state_ = FullscreenMenubarState::SHOWING;
 
+  // In 10.12. the toolbar to be janky since the UI doesn't update until the
+  // menubar finished revealing itself. To smooth things out, animate the
+  // toolbar in/out by locking/releasing its visibility instead of relying on
+  // the menubar fraction.
+  // TODO(spqchan): Figure out why it's not updating and make the toolbar drop
+  // down in sync with the menubar. See crbug.com/672254.
+  if (base::mac::IsOS10_12()) {
+    if (state_ == FullscreenMenubarState::SHOWING) {
+      [[owner_ visibilityLockController] lockToolbarVisibilityForOwner:self
+                                                         withAnimation:YES];
+    } else if (state_ == FullscreenMenubarState::HIDING) {
+      [[owner_ visibilityLockController] releaseToolbarVisibilityForOwner:self
+                                                            withAnimation:YES];
+    }
+  }
+
   menubarFraction_ = progress;
-
   [owner_ updateToolbarLayout];
 }
 
 - (BOOL)isMouseOnScreen {
   return NSMouseInRect([NSEvent mouseLocation],
                        [[browserWindowController_ window] screen].frame, false);
 }
 
 - (void)activeSpaceDidChange:(NSNotification*)notification {
   menubarFraction_ = 0.0;
   state_ = FullscreenMenubarState::HIDDEN;
+  [[owner_ visibilityLockController] releaseToolbarVisibilityForOwner:self
+                                                        withAnimation:NO];
   [owner_ updateToolbarLayout];
 }
 
 @end