Fix a crash when with chrome-ui://about/" or anything invalid...

chrome/browser/dom_ui/dom_ui_contents.cc

 // Copyright (c) 2006-2008 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/dom_ui/dom_ui_contents.h"
 
 #include "chrome/browser/debugger/debugger_contents.h"
 #include "chrome/browser/dom_ui/dev_tools_ui.h"
 #include "chrome/browser/dom_ui/dom_ui.h"
 #include "chrome/browser/dom_ui/downloads_ui.h"
@@ skipping 176 matching lines @@
 
 bool DOMUIContents::IsBookmarkBarAlwaysVisible() {
   if (InitCurrentUI(false))
     return current_ui_->IsBookmarkBarAlwaysVisible();
   return false;
 }
 
 void DOMUIContents::SetInitialFocus() {
   if (InitCurrentUI(false))
     current_ui_->SetInitialFocus();
-  else
+  else if (current_ui_)
     current_ui_->get_contents()->view()->SetInitialFocus();
 }
 
 const string16& DOMUIContents::GetTitle() const {
   // Workaround for new tab page - we may be asked for a title before
   // the content is ready, and we don't even want to display a 'loading...'
   // message, so we force it here.
   if (controller()->GetActiveEntry() &&
       controller()->GetActiveEntry()->url().host() ==
       NewTabUI::GetBaseURL().host()) {
@@ skipping 42 matching lines @@
   if (reload || url.host() != current_url_.host()) {
     // Shut down our existing DOMUI.
     delete current_ui_;
     current_ui_ = NULL;
 
     // Set up a new DOMUI.
     current_ui_ = GetDOMUIForURL(url);
     if (current_ui_) {
       current_ui_->Init();
       current_url_ = url;
-      return true;
     }
-  } else if (current_ui_) {
+  } 
+  
+  if (current_ui_)
     return true;
-  }
 
   return false;
 }
 
 // static
 const std::string DOMUIContents::GetScheme() {
   return chrome::kChromeUIScheme;
 }
 
 DOMUI* DOMUIContents::GetDOMUIForURL(const GURL &url) {
@@ skipping 16 matching lines @@
     return new DebuggerContents(this);
   }
   if (url.host() == DevToolsUI::GetBaseURL().host()) {
     return new DevToolsUI(this);
   }
 #else
   NOTIMPLEMENTED();
 #endif
   return NULL;
 }