ppapi: Cleanup class/struct forward declarations

ppapi/cpp/text_input_controller.h

 // Copyright 2013 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 PPAPI_CPP_TEXT_INPUT_CONTROLLER_H_
 #define PPAPI_CPP_TEXT_INPUT_CONTROLLER_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "ppapi/c/ppb_text_input_controller.h"
 #include "ppapi/cpp/instance_handle.h"
 #include "ppapi/cpp/var.h"
 
 /// @file
 /// This file defines the APIs for text input handling.
 
 namespace pp {
 
 class Rect;
-class Instance;
 
 /// This class can be used for giving hints to the browser about the text input
 /// status of plugins.
 class TextInputController {
  public:
   /// A constructor for creating a <code>TextInputController</code>.
   ///
   /// @param[in] instance The instance with which this resource will be
   /// associated.
   explicit TextInputController(const InstanceHandle& instance);
@@ skipping 33 matching lines @@
                              uint32_t caret,
                              uint32_t anchor);
 
  private:
   InstanceHandle instance_;
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_TEXT_INPUT_CONTROLLER_H_