WebUI: Fix lifecycle-bug when RenderFrameHost is swapped out

content/public/browser/web_ui_message_handler.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_
 
 #include <vector>
 
 #include "base/gtest_prod_util.h"
@@ skipping 17 matching lines @@
 class WebUIImpl;
 
 // Messages sent from the DOM are forwarded via the WebUI to handler
 // classes. These objects are owned by WebUI and destroyed when the
 // host is destroyed.
 class CONTENT_EXPORT WebUIMessageHandler {
  public:
   WebUIMessageHandler() : javascript_allowed_(false), web_ui_(nullptr) {}
   virtual ~WebUIMessageHandler() {}
 
+  // Call this when a page should not receive JavaScript messages.
+  void DisallowJavascript();
+
  protected:
   FRIEND_TEST_ALL_PREFIXES(WebUIMessageHandlerTest, ExtractIntegerValue);
   FRIEND_TEST_ALL_PREFIXES(WebUIMessageHandlerTest, ExtractDoubleValue);
   FRIEND_TEST_ALL_PREFIXES(WebUIMessageHandlerTest, ExtractStringValue);
 
   // Subclasses must call this once the page is ready for JavaScript calls
   // from this handler.
   void AllowJavascript();
 
-  // Call this when a page should not receive JavaScript messages.
-  void DisallowJavascript();
-
   bool IsJavascriptAllowed() const;
 
   // Helper methods:
 
   // Extract an integer value from a list Value.
   static bool ExtractIntegerValue(const base::ListValue* value, int* out_int);
 
   // Extract a floating point (double) value from a list Value.
   static bool ExtractDoubleValue(const base::ListValue* value,
                                  double* out_value);
@@ skipping 51 matching lines @@
 
   // True if the page is for JavaScript calls from this handler.
   bool javascript_allowed_;
 
   WebUI* web_ui_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_UI_MESSAGE_HANDLER_H_