Mac: Speculative fix for tracking area crashes

ui/base/cocoa/base_view.mm

Index: ui/base/cocoa/base_view.mm
diff --git a/ui/base/cocoa/base_view.mm b/ui/base/cocoa/base_view.mm
index b37b6789435d8a6da2698e72d63b1779adba2957..6f7b540aa739ce3ce81cedcf43ef513b33681edf 100644
--- a/ui/base/cocoa/base_view.mm
+++ b/ui/base/cocoa/base_view.mm
@@ -8,18 +8,57 @@ NSString* kViewDidBecomeFirstResponder =
     @"Chromium.kViewDidBecomeFirstResponder";
 NSString* kSelectionDirection = @"Chromium.kSelectionDirection";
 
-const int kTrackingOptions = NSTrackingMouseMoved |
-                             NSTrackingMouseEnteredAndExited |
-                             NSTrackingActiveAlways;
-
 @implementation BaseView
 
+- (instancetype)initWithFrame:(NSRect)frame {
+  if ((self = [super initWithFrame:frame])) {
+    [self enableTracking];
+  }
+  return self;
+}
+
+- (instancetype)initWithCoder:(NSCoder*)decoder {
+  if ((self = [super initWithCoder:decoder])) {
+    [self enableTracking];
+  }
+  return self;
+}
+
 - (void)dealloc {
+  [self disableTracking];
+  [super dealloc];
+}
+
+- (void)enableTracking {
   if (trackingArea_.get())
+    return;
+
+  NSTrackingAreaOptions trackingOptions = NSTrackingMouseEnteredAndExited |
+                                          NSTrackingMouseMoved |
+                                          NSTrackingActiveAlways |
+                                          NSTrackingInVisibleRect;
+  trackingArea_.reset([[CrTrackingArea alloc] initWithRect:NSZeroRect
+                                                   options:trackingOptions
+                                                     owner:self
+                                                  userInfo:nil]);
+  [self addTrackingArea:trackingArea_.get()];
+}
+
+- (void)disableTracking {
+  if (trackingArea_.get()) {
     [self removeTrackingArea:trackingArea_.get()];
-  trackingArea_.reset(nil);
+    trackingArea_.reset();
+  }
+}
 
-  [super dealloc];
+- (void)viewDidEndLiveResize {
+  [super viewDidEndLiveResize];
+
+  // NSTrackingInVisibleRect doesn't work correctly with Lion's window resizing,
+  // http://crbug.com/176725 / http://openradar.appspot.com/radar?id=2773401 .
+  // Work around it by reinstalling the tracking area after window resize.
+  [self disableTracking];
+  [self enableTracking];
 }
 
 - (void)mouseEvent:(NSEvent*)theEvent {
@@ -138,19 +177,4 @@ const int kTrackingOptions = NSTrackingMouseMoved |
   return new_rect;
 }
 
-- (void)updateTrackingAreas {
-  [super updateTrackingAreas];
-
-  // 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