Remove unneeded code from WebTestProxyBase.

components/test_runner/web_test_runner.h

 // Copyright 2014 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.
 
 #ifndef COMPONENTS_TEST_RUNNER_WEB_TEST_RUNNER_H_
 #define COMPONENTS_TEST_RUNNER_WEB_TEST_RUNNER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 37 matching lines @@
   // |custom_text_dump| argument.  Otherwise returns |false|.
   virtual bool HasCustomTextDump(std::string* custom_text_dump) const = 0;
 
   // Returns true if the call to WebTestProxy::captureTree will invoke
   // WebTestDelegate::captureHistoryForWindow.
   virtual bool ShouldDumpBackForwardList() const = 0;
 
   // Returns true if WebTestProxy::capturePixels should be invoked after
   // capturing text results.
   virtual bool ShouldGeneratePixelResults() = 0;
-
-  virtual bool ShouldStayOnPageAfterHandlingBeforeUnload() const = 0;
 };
 
 }  // namespace test_runner
 
 #endif  // COMPONENTS_TEST_RUNNER_WEB_TEST_RUNNER_H_