[Mac] Inform reference counted objects that hold a weak Browser* when the Browser is being destroye…

chrome/browser/ui/cocoa/find_bar/find_bar_cocoa_controller.h

 // Copyright (c) 2011 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 <Cocoa/Cocoa.h>
 
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/geometry/point.h"
 
@@ skipping 44 matching lines @@
 
   // Default width of FindBar.
   CGFloat defaultWidth_;
 };
 
 @property (readonly, nonatomic) NSView* findBarView;
 
 // Initializes a new FindBarCocoaController.
 - (id)initWithBrowser:(Browser*)browser;
 
+// Called by BrowserWindowController when the Browser is being destroyed.
+- (void)browserWillBeDestroyed;

[tapted, 2015/07/07 04:25:59]

Hm - I think this is OK to be consistent. But the lifetime is different.

FindBarCocoaController is owned by FindBarBridge which is owned by (wait for
it..) FindBarController, which is plonked into a scoped_ptr held by Browser.

FindBarBridge::~FindBarBridge() will be called reliably. It currently does
`[cocoa_controller_ release];`. It *could* be responsible for the
browserWillBeDestroyed call instead of browser_window_controller.mm. But
actually FindBarBridge and BrowserWindowController each have their own
reference. The one in browser_window_controller.mm will happen first, so I think
that's the way to go. But perhaps it needs a note to say FindBarBridge also has
a reference which will be released later.

I don't think it will make a difference, but only because
Browser::find_bar_controller_ is never destroyed once it is (lazily) created.

[jackhou1, 2015/07/07 08:33:05]

Added note in BrowserWindowController::dealloc

+
 - (void)setFindBarBridge:(FindBarBridge*)findBar;
 
 - (IBAction)close:(id)sender;
 
 - (IBAction)nextResult:(id)sender;
 
 - (IBAction)previousResult:(id)sender;
 
 // Position the find bar at the given maximum y-coordinate (the min-y of the
 // bar -- toolbar + possibly bookmark bar, but not including the infobars) with
@@ skipping 21 matching lines @@
 - (BOOL)isFindBarAnimating;
 
 // Returns the FindBar's position in the superview's coordinates, but with
 // the Y coordinate growing down.
 - (gfx::Point)findBarWindowPosition;
 
 // Returns the width of the FindBar.
 - (int)findBarWidth;
 
 @end