[Mac] Fix a crash in the cookies manager that was caused by an invalid selection.

chrome/browser/cocoa/cookies_window_controller.mm

 // Copyright (c) 2009 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/cocoa/cookies_window_controller.h"
 
 #include <vector>
 
 #include "app/l10n_util_mac.h"
 #include "app/resource_bundle.h"
@@ skipping 110 matching lines @@
     if (recurse)
       return recurse;
   }
   return nil;  // We couldn't find the node.
 }
 
 #pragma mark Window Controller
 
 @implementation CookiesWindowController
 
+@synthesize removeButtonEnabled = removeButtonEnabled_;
 @synthesize treeController = treeController_;
 
 - (id)initWithProfile:(Profile*)profile {
   DCHECK(profile);
   NSString* nibpath = [mac_util::MainAppBundle() pathForResource:@"Cookies"
                                                           ofType:@"nib"];
   if ((self = [super initWithWindowNibPath:nibpath owner:self])) {
     profile_ = profile;
 
     [self loadTreeModelFromProfile];
@@ skipping 114 matching lines @@
     if (![child isLeaf]) {
       NSOutlineView* outlineView = [notif object];
       // Tell the OutlineView to expand the NSTreeNode, not the model object.
       children = [item childNodes];
       DCHECK_EQ([children count], 1U);
       [outlineView expandItem:[children lastObject]];
     }
   }
 }
 
+- (void)outlineViewSelectionDidChange:(NSNotification*)notif {
+  // Multi-selection should be disabled in the UI, but for sanity, double-check
+  // that they can't do it here.
+  NSUInteger count = [[treeController_ selectedObjects] count];
+  if (count != 1U) {
+    DCHECK_LT(count, 1U) << "User was able to select more than one cookie node!";
+    [self setRemoveButtonEnabled:NO];
+    return;
+  }
+
+  // Go through the selection's indexPath and make sure that the node that is
+  // being referenced actually exists in the Cocoa model.
+  NSIndexPath* selection = [treeController_ selectionIndexPath];
+  NSUInteger length = [selection length];
+  CocoaCookieTreeNode* node = [self cocoaTreeModel];
+  for (NSUInteger i = 0; i < length; ++i) {
+    NSUInteger childIndex = [selection indexAtPosition:i];
+    if (childIndex >= [[node children] count]) {
+      [self setRemoveButtonEnabled:NO];
+      return;
+    }
+    node = [[node children] objectAtIndex:childIndex];
+  }
+
+  [self setRemoveButtonEnabled:YES];
+}
+
 #pragma mark Unit Testing
 
 - (CookiesTreeModelObserverBridge*)modelObserver {
   return modelObserver_.get();
 }
 
 - (NSArray*)icons {
   return icons_.get();
 }
 
@@ skipping 21 matching lines @@
   [icons_ addObject:rb.GetNSImageNamed(IDR_BOOKMARK_BAR_FOLDER)];
 
   // Create the Cocoa model.
   CookieTreeNode* root = static_cast<CookieTreeNode*>(treeModel_->GetRoot());
   scoped_nsobject<CocoaCookieTreeNode> model(
       [[CocoaCookieTreeNode alloc] initWithNode:root]);
   [self setCocoaTreeModel:model.get()];  // Takes ownership.
 }
 
 @end