Spelling correction: "nonexistant" -> "nonexistent".

chrome/browser/extensions/extensions_service.cc

 // Copyright (c) 2010 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/extensions/extensions_service.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/histogram.h"
@@ skipping 388 matching lines @@
     // the map, someone failed to update |unloaded_extension_paths_|.
     CHECK(!path.empty());
     LoadExtension(path);
   }
 }
 
 void ExtensionsService::UninstallExtension(const std::string& extension_id,
                                            bool external_uninstall) {
   Extension* extension = GetExtensionByIdInternal(extension_id, true, true);
 
-  // Callers should not send us nonexistant extensions.
+  // Callers should not send us nonexistent extensions.
   DCHECK(extension);
 
   // Notify interested parties that we're uninstalling this extension.
   NotificationService::current()->Notify(
       NotificationType::EXTENSION_UNINSTALLED,
       Source<Profile>(profile_),
       Details<Extension>(extension));
 
   // Get hold of information we need after unloading, since the extension
   // pointer will be invalid then.
@@ skipping 474 matching lines @@
       NewRunnableMethod(
           backend_.get(), &ExtensionsServiceBackend::CheckForExternalUpdates,
           killed_extensions, scoped_refptr<ExtensionsService>(this)));
 }
 
 void ExtensionsService::UnloadExtension(const std::string& extension_id) {
   // Make sure the extension gets deleted after we return from this function.
   scoped_ptr<Extension> extension(
       GetExtensionByIdInternal(extension_id, true, true));
 
-  // Callers should not send us nonexistant extensions.
+  // Callers should not send us nonexistent extensions.
   CHECK(extension.get());
 
   // Keep information about the extension so that we can reload it later
   // even if it's not permanently installed.
   unloaded_extension_paths_[extension->id()] = extension->path();
 
   // Clean up if the extension is meant to be enabled after a reload.
   disabled_extension_paths_.erase(extension->id());
 
   ExtensionDOMUI::UnregisterChromeURLOverrides(profile_,
@@ skipping 675 matching lines @@
   // Finish installing on UI thread.
   ChromeThread::PostTask(
       ChromeThread::UI, FROM_HERE,
       NewRunnableMethod(
           frontend_,
           &ExtensionsService::ContinueLoadAllExtensions,
           extensions_to_reload,
           start_time,
           true));
 }