chrome: Cleanup class/struct forward declarations

chrome/browser/android/provider/chrome_browser_provider.h

 // Copyright (c) 2012 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_PROVIDER_CHROME_BROWSER_PROVIDER_H_
 #define CHROME_BROWSER_ANDROID_PROVIDER_CHROME_BROWSER_PROVIDER_H_
 
 #include <memory>
 
 #include "base/android/jni_weak_ref.h"
@@ skipping 10 matching lines @@
 class Profile;
 
 namespace favicon {
 class FaviconService;
 }
 
 namespace history {
 class TopSites;
 }
 
-namespace sql {
-class Statement;
-}
-
 // This class implements the native methods of ChromeBrowserProvider.java
 class ChromeBrowserProvider : public bookmarks::BaseBookmarkModelObserver,
                               public history::HistoryServiceObserver {
  public:
   ChromeBrowserProvider(JNIEnv* env, jobject obj);
   void Destroy(JNIEnv*, const base::android::JavaParamRef<jobject>&);
 
   // JNI registration.
   static bool RegisterChromeBrowserProvider(JNIEnv* env);
 
@@ skipping 193 matching lines @@
 
   ScopedObserver<history::HistoryService, history::HistoryServiceObserver>
       history_service_observer_;
 
   bool handling_extensive_changes_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserProvider);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_PROVIDER_CHROME_BROWSER_PROVIDER_H_