WebView: Cleanup class/struct forward declarations

android_webview/browser/aw_metrics_service_client.h

 // Copyright 2015 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 ANDROID_WEBVIEW_BROWSER_AW_METRICS_SERVICE_CLIENT_IMPL_H_
 #define ANDROID_WEBVIEW_BROWSER_AW_METRICS_SERVICE_CLIENT_IMPL_H_
 
 #include <memory>
 #include <string>
 
 #include "android_webview/browser/aw_metrics_service_client.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "components/metrics/enabled_state_provider.h"
 #include "components/metrics/metrics_service_client.h"
 
 class PrefService;
 
 namespace base {
 class FilePath;
 }
 
 namespace metrics {
-struct ClientInfo;
 class MetricsStateManager;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace android_webview {
 
 // This singleton manages metrics for an app using any number of WebViews. The
@@ skipping 47 matching lines @@
   net::URLRequestContextGetter* request_context_;
   std::unique_ptr<metrics::MetricsStateManager> metrics_state_manager_;
   std::unique_ptr<metrics::MetricsService> metrics_service_;
 
   DISALLOW_COPY_AND_ASSIGN(AwMetricsServiceClient);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_AW_METRICS_SERVICE_CLIENT_IMPL_H_