Revert "Mac: modernize menu reveal tracking"

This reverts commit 33253a15.

Reason for revert: Broke PWA content fullscreen
https://crbug.com/1109608

Original change's description:
> Mac: modernize menu reveal tracking
> 
> The fullscreen toolbar controller currently uses undocumented Carbon
> events to track the menubar's reveal amount in fullscreen. In recent
> macOS versions, the intermediate values are no longer send and we
> only receive events when the menubar is fully shown or fully hidden.
> 
> The Mac immersive code which is still behind a flag uses a different
> technique, observing the reveal amount on a hidden titlebar accessory
> view. This *does* provide correct intermediate values.
> 
> This change extracts the reveal code from the immersive controller
> and uses it in the current fullscreen code rather than the Carbon
> event. Unfortunately, despite receiving the correct progress
> notifications, the topchrome still does a discontinuous jump, but
> we'll cross that bridge later.
> 
> Bug: 1063417
> Change-Id: I6827cafbcad58eeaabf98c6facaeb85ce3439997
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2314998
> Reviewed-by: Avi Drissman <avi@chromium.org>
> Commit-Queue: Leonard Grey <lgrey@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#791273}

TBR=avi@chromium.org,lgrey@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1063417
Change-Id: Ie70a1ce26feddaa6aec2e0f061b8dd7656fcf55e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2320409Reviewed-by: Leonard Grey <lgrey@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Leonard Grey <lgrey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791889}

chrome/browser/ui/BUILD.gn

@@ -2800,8 +2800,6 @@ static_library("ui") {
       "cocoa/fullscreen/fullscreen_toolbar_controller.mm",
       "cocoa/fullscreen/fullscreen_toolbar_mouse_tracker.h",
       "cocoa/fullscreen/fullscreen_toolbar_mouse_tracker.mm",
-      "cocoa/fullscreen/menu_reveal_monitor.h",
-      "cocoa/fullscreen/menu_reveal_monitor.mm",
       "cocoa/handoff_active_url_observer.cc",
       "cocoa/handoff_active_url_observer.h",
       "cocoa/handoff_active_url_observer_bridge.h",

chrome/browser/ui/cocoa/fullscreen/fullscreen_menubar_tracker.mm

@@ -4,19 +4,56 @@
 
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_menubar_tracker.h"
 
+#include <Carbon/Carbon.h>
 #include <QuartzCore/QuartzCore.h>
 
 #include "base/mac/mac_util.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/stl_util.h"
 #import "chrome/browser/ui/cocoa/fullscreen/fullscreen_toolbar_controller.h"
-#import "chrome/browser/ui/cocoa/fullscreen/menu_reveal_monitor.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;
+
+// TODO(https://crbug.com/1063417): Replace this with something that works
+// on modern macOS versions.
+OSStatus MenuBarRevealHandler(EventHandlerCallRef handler,
+                              EventRef event,
+                              void* context) {
+  FullscreenMenubarTracker* self =
+      static_cast<FullscreenMenubarTracker*>(context);
+
+  // If Chrome has multiple fullscreen windows in their own space, the Handler
+  // becomes flaky and might start receiving kMenuBarRevealEventKind events
+  // from another space. Since the menubar in the another space is in either a
+  // shown or hidden state, it will give us a reveal fraction of 0.0 or 1.0.
+  // As such, we should ignore the kMenuBarRevealEventKind event if it gives
+  // us a fraction of 0.0 or 1.0, and rely on kEventMenuBarShown and
+  // kEventMenuBarHidden to set these values.
+  if (GetEventKind(event) == kMenuBarRevealEventKind) {
+    CGFloat revealFraction = 0;
+    GetEventParameter(event, FOUR_CHAR_CODE('rvlf'), typeCGFloat, NULL,
+                      sizeof(CGFloat), NULL, &revealFraction);
+    if (revealFraction > 0.0 && revealFraction < 1.0)
+      [self setMenubarProgress:revealFraction];
+  } else if (GetEventKind(event) == kEventMenuBarShown) {
+    [self setMenubarProgress:1.0];
+  } else {
+    [self setMenubarProgress:0.0];
+  }
+
+  return CallNextEventHandler(handler, event);
+}
+
+}  // end namespace
+
 @interface FullscreenMenubarTracker () {
   FullscreenToolbarController* _controller;        // weak
 
-  base::scoped_nsobject<MenuRevealMonitor> menu_reveal_monitor_;
+  // A Carbon event handler that tracks the revealed fraction of the menubar.
+  EventHandlerRef _menubarTrackingHandler;
 }
 
 // Returns YES if the mouse is on the same screen as the window.
@@ -35,12 +72,22 @@
     _controller = controller;
     _state = FullscreenMenubarState::HIDDEN;
 
-    __block FullscreenMenubarTracker* nonCaptureSelf = self;
-    menu_reveal_monitor_.reset([[MenuRevealMonitor alloc]
-        initWithWindow:[controller window]
-         changeHandler:^(double reveal_amount) {
-           [nonCaptureSelf setMenubarProgress:reveal_amount];
-         }]);
+    // Install the Carbon event handler for the menubar show, hide and
+    // undocumented reveal event.
+    EventTypeSpec eventSpecs[3];
+
+    eventSpecs[0].eventClass = kEventClassMenu;
+    eventSpecs[0].eventKind = kMenuBarRevealEventKind;
+
+    eventSpecs[1].eventClass = kEventClassMenu;
+    eventSpecs[1].eventKind = kEventMenuBarShown;
+
+    eventSpecs[2].eventClass = kEventClassMenu;
+    eventSpecs[2].eventKind = kEventMenuBarHidden;
+
+    InstallApplicationEventHandler(NewEventHandlerUPP(&MenuBarRevealHandler),
+                                   base::size(eventSpecs), eventSpecs, self,
+                                   &_menubarTrackingHandler);
 
     // Register for Active Space change notifications.
     [[[NSWorkspace sharedWorkspace] notificationCenter]
@@ -53,8 +100,9 @@
 }
 
 - (void)dealloc {
+  RemoveEventHandler(_menubarTrackingHandler);
   [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:self];
-  menu_reveal_monitor_.reset();
+
   [super dealloc];
 }
 

chrome/browser/ui/cocoa/fullscreen/menu_reveal_monitor.h

-// Copyright 2020 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.
-
-#ifndef CHROME_BROWSER_UI_COCOA_FULLSCREEN_MENU_REVEAL_MONITOR_H_
-#define CHROME_BROWSER_UI_COCOA_FULLSCREEN_MENU_REVEAL_MONITOR_H_
-
-#import <Cocoa/Cocoa.h>
-
-// MenuRevealMonitor tracks visibility of the menu bar associated with |window|,
-// and calls |handler| when it changes. In fullscreen, when the mouse pointer
-// moves to or away from the top of the screen, |handler| will be called several
-// times with a number between zero and one indicating how much of the menu bar
-// is visible.
-@interface MenuRevealMonitor : NSObject
-- (instancetype)initWithWindow:(NSWindow*)window
-                 changeHandler:(void (^)(double))handler
-    NS_DESIGNATED_INITIALIZER;
-- (instancetype)init NS_UNAVAILABLE;
-@end
-
-#endif  // CHROME_BROWSER_UI_COCOA_FULLSCREEN_MENU_REVEAL_MONITOR_H_

chrome/browser/ui/cocoa/fullscreen/menu_reveal_monitor.mm

-// Copyright 2020 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/menu_reveal_monitor.h"
-
-#include "base/mac/foundation_util.h"
-#include "base/mac/scoped_block.h"
-#include "base/mac/scoped_nsobject.h"
-
-static NSString* const kRevealAmountKeyPath = @"revealAmount";
-
-@implementation MenuRevealMonitor {
-  base::mac::ScopedBlock<void (^)(double)> _change_handler;
-  base::scoped_nsobject<NSTitlebarAccessoryViewController> _accVC;
-}
-
-- (instancetype)initWithWindow:(NSWindow*)window
-                 changeHandler:(void (^)(double))handler {
-  if ((self = [super init])) {
-    _change_handler.reset([handler copy]);
-    _accVC.reset([[NSTitlebarAccessoryViewController alloc] init]);
-    auto* accVC = _accVC.get();
-    accVC.view = [[[NSView alloc] initWithFrame:NSZeroRect] autorelease];
-    [accVC addObserver:self
-            forKeyPath:kRevealAmountKeyPath
-               options:NSKeyValueObservingOptionNew
-               context:nil];
-    [window addTitlebarAccessoryViewController:accVC];
-  }
-  return self;
-}
-
-- (void)dealloc {
-  [_accVC removeObserver:self forKeyPath:kRevealAmountKeyPath];
-  [_accVC removeFromParentViewController];
-  [super dealloc];
-}
-
-- (void)observeValueForKeyPath:(NSString*)keyPath
-                      ofObject:(id)object
-                        change:(NSDictionary<NSKeyValueChangeKey, id>*)change
-                       context:(void*)context {
-  double revealAmount =
-      base::mac::ObjCCastStrict<NSNumber>(change[NSKeyValueChangeNewKey])
-          .doubleValue;
-  _change_handler.get()(revealAmount);
-}
-@end

chrome/browser/ui/views/frame/immersive_mode_controller_mac.mm

@@ -9,7 +9,6 @@
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/weak_ptr.h"
-#include "chrome/browser/ui/cocoa/fullscreen/menu_reveal_monitor.h"
 #include "chrome/browser/ui/cocoa/scoped_menu_bar_lock.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/frame/immersive_mode_controller.h"
@@ -22,6 +21,56 @@ namespace {
 const CGFloat kMenuBarLockPadding = 50;
 }
 
+// MenuRevealMonitor tracks visibility of the menu bar associated with |window|,
+// and calls |handler| when it changes. In fullscreen, when the mouse pointer
+// moves to or away from the top of the screen, |handler| will be called several
+// times with a number between zero and one indicating how much of the menu bar
+// is visible.
+@interface MenuRevealMonitor : NSObject
+- (instancetype)initWithWindow:(NSWindow*)window
+                 changeHandler:(void (^)(double))handler
+    NS_DESIGNATED_INITIALIZER;
+- (instancetype)init NS_UNAVAILABLE;
+@end
+
+@implementation MenuRevealMonitor {
+  base::mac::ScopedBlock<void (^)(double)> _change_handler;
+  base::scoped_nsobject<NSTitlebarAccessoryViewController> _accVC;
+}
+
+- (instancetype)initWithWindow:(NSWindow*)window
+                 changeHandler:(void (^)(double))handler {
+  if ((self = [super init])) {
+    _change_handler.reset([handler copy]);
+    _accVC.reset([[NSTitlebarAccessoryViewController alloc] init]);
+    auto* accVC = _accVC.get();
+    accVC.view = [[[NSView alloc] initWithFrame:NSZeroRect] autorelease];
+    [accVC addObserver:self
+            forKeyPath:@"revealAmount"
+               options:NSKeyValueObservingOptionNew
+               context:nil];
+    [window addTitlebarAccessoryViewController:accVC];
+  }
+  return self;
+}
+
+- (void)dealloc {
+  [_accVC removeObserver:self forKeyPath:@"revealAmount"];
+  [_accVC removeFromParentViewController];
+  [super dealloc];
+}
+
+- (void)observeValueForKeyPath:(NSString*)keyPath
+                      ofObject:(id)object
+                        change:(NSDictionary<NSKeyValueChangeKey, id>*)change
+                       context:(void*)context {
+  double revealAmount =
+      base::mac::ObjCCastStrict<NSNumber>(change[NSKeyValueChangeNewKey])
+          .doubleValue;
+  _change_handler.get()(revealAmount);
+}
+@end
+
 // ImmersiveToolbarOverlayView performs two functions. First, it hitTests to its
 // superview (BridgedContentView) to block mouse events from hitting siblings
 // which the toolbar might overlap, like RenderWidgetHostView. It also sets up a