blimp: Cleanup class/struct forward declarations

blimp/client/core/settings/android/blimp_settings_android.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 BLIMP_CLIENT_CORE_SETTINGS_ANDROID_BLIMP_SETTINGS_ANDROID_H_
 #define BLIMP_CLIENT_CORE_SETTINGS_ANDROID_BLIMP_SETTINGS_ANDROID_H_
 
 #include <memory>
 
 #include "base/android/jni_android.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
 #include "blimp/client/core/session/identity_source.h"
 #include "blimp/client/core/session/network_event_observer.h"
 
 namespace blimp {
 namespace client {
 
-class BlimpClientContextImplAndroid;
 class BlimpSettingsDelegate;
 
 // JNI bridge between AboutBlimpPreferences.java and native code.
 class BlimpSettingsAndroid : public IdentityProvider::Observer,
                              public NetworkEventObserver {
  public:
   static bool RegisterJni(JNIEnv* env);
   static BlimpSettingsAndroid* FromJavaObject(
       JNIEnv* env,
       const base::android::JavaRef<jobject>& jobj);
@@ skipping 27 matching lines @@
   // Delegate that provides functions needed by settings.
   BlimpSettingsDelegate* delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(BlimpSettingsAndroid);
 };
 
 }  // namespace client
 }  // namespace blimp
 
 #endif  //  BLIMP_CLIENT_CORE_SETTINGS_ANDROID_BLIMP_SETTINGS_ANDROID_H_