Mac: Speculative fix for tracking area crashes

ui/base/cocoa/base_view.mm

 // 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.
 
 #include "ui/base/cocoa/base_view.h"
 
 NSString* kViewDidBecomeFirstResponder =
     @"Chromium.kViewDidBecomeFirstResponder";
 NSString* kSelectionDirection = @"Chromium.kSelectionDirection";
 
-const int kTrackingOptions = NSTrackingMouseMoved |
-                             NSTrackingMouseEnteredAndExited |
-                             NSTrackingActiveAlways;
+@implementation BaseView
 
-@implementation BaseView
+- (instancetype)initWithFrame:(NSRect)frame {
+  if ((self = [super initWithFrame:frame])) {
+    [self initBaseView];
+  }
+  return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder*)decoder {
+  if ((self = [super initWithCoder:decoder])) {
+    [self initBaseView];
+  }
+  return self;
+}
+
+- (void)initBaseView {
+  trackingArea_.reset(
+      [[CrTrackingArea alloc] initWithRect:NSZeroRect
+                                   options:NSTrackingMouseMoved |
+                                           NSTrackingMouseEnteredAndExited |
+                                           NSTrackingActiveAlways |
+                                           NSTrackingInVisibleRect
+                                     owner:self
+                                  userInfo:nil]);
+  [self addTrackingArea:trackingArea_.get()];
+}
 
 - (void)dealloc {
   if (trackingArea_.get())
     [self removeTrackingArea:trackingArea_.get()];
   trackingArea_.reset(nil);
 
   [super dealloc];
 }
 
 - (void)mouseEvent:(NSEvent*)theEvent {
@@ skipping 105 matching lines @@
   new_rect.set_y(NSHeight([self bounds]) - new_rect.bottom());
   return new_rect;
 }
 
 - (NSRect)flipRectToNSRect:(gfx::Rect)rect {
   NSRect new_rect(NSRectFromCGRect(rect.ToCGRect()));
   new_rect.origin.y = NSHeight([self bounds]) - NSMaxY(new_rect);
   return new_rect;
 }
 
-- (void)updateTrackingAreas {
-  [super updateTrackingAreas];

[Nico, 2015/02/24 21:00:18]

Could we set a flag in dealloc and not add a new tracking area here if that flag
is set? Could that fix the crash without requiring focus for the bug fix?

[Andre, 2015/02/24 21:20:46]

I thought about that, but ended up not being confident that it will fix the
crash.
Looking at the zombie_dealloc bt from the original bug description, the
crashing tracking area is the one that was deleted in -[BaseView dealloc].
I think that rules out my speculation in https://crbug.com/315379#c8, and
more likely to be an AppKit bug somewhere.

-
-  // NSTrackingInVisibleRect doesn't work correctly with Lion's window resizing,
-  // http://crbug.com/176725 / http://openradar.appspot.com/radar?id=2773401 .
-  // Tear down old tracking area and create a new one as workaround.
-  if (trackingArea_.get())
-    [self removeTrackingArea:trackingArea_.get()];
-  trackingArea_.reset([[CrTrackingArea alloc] initWithRect:[self bounds]
-                                                   options:kTrackingOptions
-                                                     owner:self
-                                                  userInfo:nil]);
-  [self addTrackingArea:trackingArea_.get()];
-}
-
 @end