Switching VirtualKeyboardPrivate keyboard config call stack to receive HasInputDevices() responce a…

extensions/browser/api/virtual_keyboard_private/virtual_keyboard_delegate.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_API_VIRTUAL_KEYBOARD_PRIVATE_VIRTUAL_KEYBOARD_DELEGATE_H_
 #define EXTENSIONS_BROWSER_API_VIRTUAL_KEYBOARD_PRIVATE_VIRTUAL_KEYBOARD_DELEGATE_H_
 
+#include "base/callback.h"
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "base/values.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace extensions {
 
 class VirtualKeyboardDelegate {
  public:
   virtual ~VirtualKeyboardDelegate() {}
 
+  using OnKeyboardSettingsCallback =
+      base::Callback<void(std::unique_ptr<base::DictionaryValue> settings)>;
+
   // Fetch information about the preferred configuration of the keyboard. On
-  // exit, |settings| is populated with the keyboard configuration. Returns true
-  // if successful.
-  virtual bool GetKeyboardConfig(base::DictionaryValue* settings) = 0;
+  // exit, |settings| is populated with the keyboard configuration if execution
+  // is successful, otherwise it's set to nullptr.
+  virtual void GetKeyboardConfig(
+      OnKeyboardSettingsCallback on_settings_callback) = 0;
 
   // Dismiss the virtual keyboard without changing input focus. Returns true if
   // successful.
   virtual bool HideKeyboard() = 0;
 
   // Insert |text| verbatim into a text area. Returns true if successful.
   virtual bool InsertText(const base::string16& text) = 0;
 
   // Notifiy system that keyboard loading is complete. Used in UMA stats to
   // track loading performance. Returns true if the notification was handled.
@@ skipping 29 matching lines @@
   // Sets virtual keyboard window mode.
   virtual bool SetVirtualKeyboardMode(int mode_enum) = 0;
 
   // Sets requested virtual keyboard state.
   virtual bool SetRequestedKeyboardState(int state_enum) = 0;
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_VIRTUAL_KEYBOARD_PRIVATE_VIRTUAL_KEYBOARD_DELEGATE_H_