Fix leaks found by valgrind (which now works on the Mac!)...

chrome/browser/cocoa/bookmark_menu_bridge.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.
 
 #include "chrome/browser/cocoa/bookmark_menu_bridge.h"
 #import <AppKit/AppKit.h>
 #include "base/sys_string_conversions.h"
 #include "chrome/app/chrome_dll_resource.h"  // IDC_BOOKMARK_MENU
 #import "chrome/browser/app_controller_mac.h"
 #include "chrome/browser/browser.h"
 #include "chrome/browser/browser_list.h"
 #import "chrome/browser/cocoa/bookmark_menu_cocoa_controller.h"
 #include "chrome/browser/profile.h"
 #include "chrome/browser/profile_manager.h"
 
 BookmarkMenuBridge::BookmarkMenuBridge()
-    : controller_([[BookmarkMenuCocoaController alloc] initWithBridge:this]) {
+    : controller_([[BookmarkMenuCocoaController alloc] initWithBridge:this]),
+      observing_(true) {
   BrowserList::AddObserver(this);
 }
 
 BookmarkMenuBridge::~BookmarkMenuBridge() {
-  GetBookmarkModel()->RemoveObserver(this);
+  if (observing_)
+    BrowserList::RemoveObserver(this);
+  BookmarkModel *model = GetBookmarkModel();
+  if (model)
+    model->RemoveObserver(this);
   [controller_ release];
 }
 
 NSMenu* BookmarkMenuBridge::BookmarkMenu() {
   NSMenu* bookmark_menu = [[[NSApp mainMenu] itemWithTag:IDC_BOOKMARK_MENU]
                             submenu];
   return bookmark_menu;
 }
 
 void BookmarkMenuBridge::Loaded(BookmarkModel* model) {
@@ skipping 58 matching lines @@
 void BookmarkMenuBridge::OnBrowserRemoving(const Browser* browser) {
   // Intentionally empty -- we don't care, but pure virtual so we must
   // implement.
 }
 
 // The current browser has changed; update the bookmark menus.  For
 // our use, we only care about the first one to know when a profile is
 // complete.
 void BookmarkMenuBridge::OnBrowserSetLastActive(const Browser* browser) {
   BrowserList::RemoveObserver(this);
+  observing_ = false;
   BookmarkModel* model = GetBookmarkModel();
   model->AddObserver(this);
   if (model->IsLoaded())
     Loaded(model);
 }
 
 BookmarkModel* BookmarkMenuBridge::GetBookmarkModel() {
   // In incognito mode we use the main profile's bookmarks.
   // Thus, we don't return browser_->profile()->GetBookmarkModel().
   Profile* profile = GetDefaultProfile();
@@ skipping 42 matching lines @@
     [item setAction:@selector(openBookmarkMenuItem:)];
     [item setTag:child->id()];
     [menu addItem:item];
     if (child->is_folder()) {
       NSMenu* submenu = [[[NSMenu alloc] initWithTitle:title] autorelease];
       [menu setSubmenu:submenu forItem:item];
       AddNodeToMenu(child, submenu);  // recursive call
     }
   }
 }