Display local signin error without browser and record the path of selected profile in user manager.

chrome/browser/ui/webui/signin/signin_error_handler.h

 // Copyright 2016 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_UI_WEBUI_SIGNIN_SIGNIN_ERROR_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_SIGNIN_SIGNIN_ERROR_HANDLER_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "content/public/browser/web_ui_message_handler.h"
 
 class Browser;
 class ProfileAttributesEntry;
 
 namespace base {
 class ListValue;
 }
 
 class SigninErrorHandler : public content::WebUIMessageHandler {
  public:
-  SigninErrorHandler() {}
+  // Create a handler depends on whether the error ui is displayed in browser
+  // window or user manager.
+  static SigninErrorHandler* Create(bool is_system_profile);
+
   ~SigninErrorHandler() override {}
 
   // content::WebUIMessageHandler:
   void RegisterMessages() override;
 
   // Sets the existing profile entry that has the same username used for signin.
   // This function is called when the signin error is a duplicate account error.
   void set_duplicate_profile_entry(
       const ProfileAttributesEntry* duplicate_profile_entry) {
     duplicate_profile_entry_ = duplicate_profile_entry;
   }
 
  protected:
+  SigninErrorHandler() {}
+
   // Handles "switch" message from the page. No arguments.
   // This message is sent when the user switches to the existing profile of the
   // same username used for signin.
   virtual void HandleSwitchToExistingProfile(const base::ListValue* args);
 
   // Handles "confirm" message from the page. No arguments.
   // This message is sent when the user acknowledges the signin error.
   virtual void HandleConfirm(const base::ListValue* args);
 
   // Handles "learnMore" message from the page. No arguments.
   // This message is sent when the user clicks on the "Learn more" link in the
   // signin error dialog, which closes the dialog and takes the user to the
   // Chrome Help page about fixing sync problems.
   virtual void HandleLearnMore(const base::ListValue* args);
 
   // Handles the web ui message sent when the html content is done being laid
   // out and it's time to resize the native view hosting it to fit. |args| is
   // a single integer value for the height the native view should resize to.
   virtual void HandleInitializedWithSize(const base::ListValue* args);
 
-  void CloseDialog();
+  virtual void CloseDialog();
 
  private:
   const ProfileAttributesEntry* duplicate_profile_entry_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(SigninErrorHandler);
 };
 
+// A Web UI message handler for signin error ui that is displayed without
+// browser window.
+class SigninErrorWithoutBrowserHandler : public SigninErrorHandler {
+ public:
+  SigninErrorWithoutBrowserHandler();
+
+ protected:
+  void CloseDialog() override;

[tommycli, 2016/09/21 18:26:59]

nit: Such a small difference does not seem worth making a class hierarchy for.
Maybe just a boolean flag within SigninErrorHandler?

[zmin, 2016/09/21 21:21:37]

I think you're right. There is only one conditional statement anyway. Subclass
do looks heavy.

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SigninErrorWithoutBrowserHandler);
+};
+
 #endif  // CHROME_BROWSER_UI_WEBUI_SIGNIN_SIGNIN_ERROR_HANDLER_H_