chrome: Cleanup class/struct forward declarations

chrome/browser/android/omnibox/autocomplete_controller_android.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 CHROME_BROWSER_ANDROID_OMNIBOX_AUTOCOMPLETE_CONTROLLER_ANDROID_H_
 #define CHROME_BROWSER_ANDROID_OMNIBOX_AUTOCOMPLETE_CONTROLLER_ANDROID_H_
 
 #include <memory>
 #include <string>
 
 #include "base/android/jni_weak_ref.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/metrics/proto/omnibox_event.pb.h"
 #include "components/omnibox/browser/autocomplete_controller_delegate.h"
 #include "components/omnibox/browser/autocomplete_input.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/notification_service.h"
 
 class AutocompleteController;
 struct AutocompleteMatch;
 class AutocompleteResult;
 class Profile;
-class Tab;
 
 // The native part of the Java AutocompleteController class.
 class AutocompleteControllerAndroid : public AutocompleteControllerDelegate,
                                       public KeyedService {
  public:
   explicit AutocompleteControllerAndroid(Profile* profile);
 
   // Methods that forward to AutocompleteController:
   void Start(JNIEnv* env,
              const base::android::JavaRef<jobject>& obj,
@@ skipping 106 matching lines @@
   JavaObjectWeakGlobalRef weak_java_autocomplete_controller_android_;
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(AutocompleteControllerAndroid);
 };
 
 // Registers the LocationBar native method.
 bool RegisterAutocompleteControllerAndroid(JNIEnv* env);
 
 #endif  // CHROME_BROWSER_ANDROID_OMNIBOX_AUTOCOMPLETE_CONTROLLER_ANDROID_H_