MacViews: Fix receiving of mouseexit events.

ui/views/cocoa/bridged_content_view.mm

 // Copyright 2014 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 "ui/views/cocoa/bridged_content_view.h"
 
 #include "base/logging.h"
 #import "base/mac/mac_util.h"
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/sdk_forward_declarations.h"
@@ skipping 298 matching lines @@
   DCHECK(bounds.origin().IsOrigin());
   NSRect initialFrame = NSMakeRect(0, 0, bounds.width(), bounds.height());
   if ((self = [super initWithFrame:initialFrame])) {
     hostedView_ = viewToHost;
 
     // Apple's documentation says that NSTrackingActiveAlways is incompatible
     // with NSTrackingCursorUpdate, so use NSTrackingActiveInActiveApp.
     cursorTrackingArea_.reset([[CrTrackingArea alloc]
         initWithRect:NSZeroRect
              options:NSTrackingMouseMoved | NSTrackingCursorUpdate |
-                     NSTrackingActiveInActiveApp | NSTrackingInVisibleRect
+                     NSTrackingActiveInActiveApp | NSTrackingInVisibleRect |
+                     NSTrackingMouseEnteredAndExited
                owner:self
             userInfo:nil]);
     [self addTrackingArea:cursorTrackingArea_.get()];
 
     // Get notified whenever Full Keyboard Access mode is changed.
     [[NSDistributedNotificationCenter defaultCenter]
         addObserver:self
            selector:@selector(onFullKeyboardAccessModeChanged:)
                name:kFullKeyboardAccessChangedNotification
              object:nil];
@@ skipping 1102 matching lines @@
   return [hostedView_->GetNativeViewAccessible() accessibilityHitTest:point];
 }
 
 - (id)accessibilityFocusedUIElement {
   if (!hostedView_)
     return nil;
   return [hostedView_->GetNativeViewAccessible() accessibilityFocusedUIElement];
 }
 
 @end