Use about:blank as the failback URL if the filter denies a navigation.

content/browser/renderer_host/render_view_host_unittest.cc

 // Copyright (c) 2012 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 "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/renderer_host/test_render_view_host.h"
 #include "content/browser/tab_contents/navigation_controller_impl.h"
 #include "content/browser/tab_contents/test_tab_contents.h"
 #include "content/common/view_messages.h"
 #include "content/public/browser/navigation_entry.h"
@@ skipping 115 matching lines @@
 TEST_F(RenderViewHostTest, StartDragging) {
   TestTabContents* tab_contents = contents();
   MockDraggingRenderViewHostDelegateView view_delegate;
   tab_contents->set_view_delegate(&view_delegate);
 
   WebDropData drop_data;
   GURL file_url = GURL("file:///home/user/secrets.txt");
   drop_data.url = file_url;
   drop_data.html_base_url = file_url;
   test_rvh()->TestOnMsgStartDragging(drop_data);
-  EXPECT_TRUE(view_delegate.drag_url().is_empty());
-  EXPECT_TRUE(view_delegate.html_base_url().is_empty());
+  EXPECT_EQ(GURL("about:blank"), view_delegate.drag_url());
+  EXPECT_EQ(GURL("about:blank"), view_delegate.html_base_url());
 
   GURL http_url = GURL("http://www.domain.com/index.html");
   drop_data.url = http_url;
   drop_data.html_base_url = http_url;
   test_rvh()->TestOnMsgStartDragging(drop_data);
   EXPECT_EQ(http_url, view_delegate.drag_url());
   EXPECT_EQ(http_url, view_delegate.html_base_url());
 
   GURL https_url = GURL("https://www.domain.com/index.html");
   drop_data.url = https_url;
@@ skipping 56 matching lines @@
   // the code actually expects it to have at least one int para, this this
   // bogus message will not fail at de-serialization but should fail in
   // OnMsgInputEventAck() processing.
   IPC::Message message(0, ViewHostMsg_HandleInputEvent_ACK::ID,
                        IPC::Message::PRIORITY_NORMAL);
   test_rvh()->TestOnMessageReceived(message);
   EXPECT_EQ(1, process()->bad_msg_count());
 }
 
 #endif