IDL: Remove support for [LogPreviousValue] extended attribute

public/web/WebDOMActivityLogger.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 26 matching lines @@
 #include <v8.h>
 
 namespace blink {
 
 class WebDOMActivityLogger {
 public:
     virtual ~WebDOMActivityLogger() { }
 
     virtual void logGetter(const WebString& apiName, const WebURL& url, const WebString& title) { }
     virtual void logSetter(const WebString& apiName, const v8::Handle<v8::Value>& newValue, const WebURL& url, const WebString& title) { }
-    virtual void logSetter(const WebString& apiName, const v8::Handle<v8::Value>& newValue, const v8::Handle<v8::Value>& oldValue, const WebURL& url, const WebString& title) { }

[Jens Widell, 2014/08/27 11:57:38]

This is implemented in extensions/renderer/dom_activity_logger.cc, but not using
OVERRIDE, so removing it here will not break compilation (or change behavior.)

     virtual void logMethod(const WebString& apiName, int argc, const v8::Handle<v8::Value>* argv, const WebURL& url, const WebString& title) { }
     virtual void logEvent(const WebString& eventName, int argc, const WebString* argv, const WebURL& url, const WebString& title) { }
 };
 
 // Checks if a logger already exists for the world identified by worldId and
 // extensionID (worldId may be 0 identifying the main world). Extension ID is
 // used only in the case of main world and ignored otherwise.
 BLINK_EXPORT bool hasDOMActivityLogger(int worldId, const WebString& extensionId);
 
 // Checks if the provided logger is non-null and if so associates it with the
 // world identified by worldId and extension ID (worldId may be 0 identifying
 // the main world). The extension ID is ignored for other worlds than the main
 // one.
 BLINK_EXPORT void setDOMActivityLogger(int worldId, const WebString& extensionId, WebDOMActivityLogger*);
 
 } // namespace blink
 
 #endif