IDL: Remove support for [LogPreviousValue] extended attribute

Source/web/tests/ActivityLoggerTest.cpp

 // 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.
 
 #include "config.h"
 
 #include "FrameTestHelpers.h"
 #include "bindings/core/v8/ScriptController.h"
 #include "bindings/core/v8/V8DOMActivityLogger.h"
 #include "web/WebLocalFrameImpl.h"
@@ skipping 15 matching lines @@
     void logGetter(const String& apiName) OVERRIDE
     {
         m_loggedActivities.append(apiName);
     }
 
     void logSetter(const String& apiName, const v8::Handle<v8::Value>& newValue) OVERRIDE
     {
         m_loggedActivities.append(apiName + " | " + toCoreStringWithUndefinedOrNullCheck(newValue));
     }
 
-    void logSetter(const String& apiName, const v8::Handle<v8::Value>& newValue, const v8::Handle<v8::Value>& oldValue) OVERRIDE
-    {
-        m_loggedActivities.append(apiName + " | " + toCoreStringWithUndefinedOrNullCheck(oldValue) + " | " + toCoreStringWithUndefinedOrNullCheck(newValue));
-    }
-
     void logMethod(const String& apiName, int argc, const v8::Handle<v8::Value>* argv) OVERRIDE
     {
         String activityString = apiName;
         for (int i = 0; i  < argc; i++)
             activityString = activityString + " | " + toCoreStringWithUndefinedOrNullCheck(argv[i]);
         m_loggedActivities.append(activityString);
     }
 
     void logEvent(const String& eventName, int argc, const String* argv) OVERRIDE
     {
@@ skipping 436 matching lines @@
         "blinkAddElement | script | data:text/html;charset=utf-8,D\n"
         "blinkRequestResource | Script | data:text/html;charset=utf-8,D\n"
         "blinkRequestResource | XMLHttpRequest | data:text/html;charset=utf-8,E";
     executeScriptInMainWorld(code);
     ASSERT_TRUE(verifyActivities(""));
     executeScriptInIsolatedWorld(code);
     ASSERT_TRUE(verifyActivities(expectedActivities));
 }
 
 } // namespace