Fix a crash in the extension system when sending response back

chrome/browser/extensions/extension_function.h

 // Copyright (c) 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_
 
 #include <string>
 
 #include "base/values.h"
@@ skipping 10 matching lines @@
   } while (0)
 
 // Abstract base class for extension functions the ExtensionFunctionDispatcher
 // knows how to dispatch to.
 //
 // TODO(aa): This will have to become reference counted when we introduce
 // APIs that live beyond a single stack frame.
 class ExtensionFunction {
  public:
   ExtensionFunction() : request_id_(-1), has_callback_(false) {}
+  virtual ~ExtensionFunction() {}
 
   // Specifies the name of the function.
   virtual void SetName(const std::string& name) { }
 
   // Specifies the raw arguments to the function, as a JSON-encoded string.
   virtual void SetArgs(const std::string& args) = 0;
 
   // Retrieves the results of the function as a JSON-encoded string (may
   // be empty).
   virtual const std::string GetResult() = 0;
@@ skipping 31 matching lines @@
  private:
   DISALLOW_COPY_AND_ASSIGN(ExtensionFunction);
 };
 
 // Base class for an extension function that runs asynchronously *relative to
 // the browser's UI thread*.
 // TODO(aa) Remove this extra level of inheritance once the browser stops
 // parsing JSON (and instead uses custom serialization of Value objects).
 class AsyncExtensionFunction : public ExtensionFunction {
  public:
-  AsyncExtensionFunction() : bad_message_(false) {}
+  AsyncExtensionFunction() : args_(NULL), bad_message_(false) {}
   virtual ~AsyncExtensionFunction() {}
 
   virtual void SetArgs(const std::string& args);
   virtual const std::string GetResult();
   virtual const std::string GetError() { return error_; }
   virtual void Run() = 0;
 
  protected:
   void SendResponse(bool success);
 
   std::string extension_id();
 
   Profile* profile();
 
-  // The arguments to the API. Only non-null if argument were specfied.
+  // The arguments to the API. Only non-null if argument were specified.
   Value* args_;
 
   // The result of the API. This should be populated by the derived class before
   // Run() returns.
   scoped_ptr<Value> result_;
 
   // Any detailed error from the API. This should be populated by the derived
   // class before Run() returns.
   std::string error_;
 
@@ skipping 22 matching lines @@
 
   virtual void Run() {
     SendResponse(RunImpl());
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncExtensionFunction);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_FUNCTION_H_