Avoid null ptr access in AutomationProvider::GetTabTitle(), fixes http://crbug.com/11132,...

chrome/browser/automation/automation_provider.cc

 // Copyright (c) 2006-2009 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/automation/automation_provider.h"
 
 #include "base/file_version_info.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
@@ skipping 1729 matching lines @@
       *tab_handle = tab_tracker_->Add(&tab_contents->controller());
     }
   }
 }
 
 void AutomationProvider::GetTabTitle(int handle, int* title_string_size,
                                      std::wstring* title) {
   *title_string_size = -1;  // -1 is the error code
   if (tab_tracker_->ContainsHandle(handle)) {
     NavigationController* tab = tab_tracker_->GetResource(handle);
-    *title = UTF16ToWideHack(tab->GetActiveEntry()->title());
+    NavigationEntry* entry = tab->GetActiveEntry();
+    *title = std::wstring();
+    if (entry != NULL) {
+      *title = UTF16ToWideHack(entry->title());
+    }
     *title_string_size = static_cast<int>(title->size());
   }
 }
 
 void AutomationProvider::GetTabIndex(int handle, int* tabstrip_index) {
   *tabstrip_index = -1;  // -1 is the error code
 
   if (tab_tracker_->ContainsHandle(handle)) {
     NavigationController* tab = tab_tracker_->GetResource(handle);
     Browser* browser = Browser::GetBrowserForController(tab, NULL);
@@ skipping 1116 matching lines @@
         DLOG(WARNING) << "SetParent failed. Error 0x%x" << GetLastError();
     }
   }
 }
 #endif
 
 void AutomationProvider::GetWindowTitle(int handle, string16* text) {
   gfx::NativeWindow window = window_tracker_->GetResource(handle);
   text->assign(platform_util::GetWindowTitle(window));
 }