Record document mode histogram in UMA on every upload.

chrome/browser/metrics/chrome_metrics_service_client.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_METRICS_CHROME_METRICS_SERVICE_CLIENT_H_
 #define CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICE_CLIENT_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 149 matching lines @@
   // MetricsService. Has the same lifetime as |metrics_service_|.
   PluginMetricsProvider* plugin_metrics_provider_;
 #endif
 
 #if defined(OS_WIN)
   // The GoogleUpdateMetricsProviderWin instance that was registered with
   // MetricsService. Has the same lifetime as |metrics_service_|.
   GoogleUpdateMetricsProviderWin* google_update_metrics_provider_;
 #endif
 
-#if !defined(OS_CHROMEOS) && !defined(OS_IOS)
-  // The SigninStatusMetricsProvider instance that was registered with
-  // MetricsService. Has the same lifetime as |metrics_service_|.
-  SigninStatusMetricsProvider* signin_status_metrics_provider_;
-#endif
-
   // Callback that is called when initial metrics gathering is complete.
   base::Closure finished_gathering_initial_metrics_callback_;
 
   // The MemoryGrowthTracker instance that tracks memory usage growth in
   // MemoryDetails.
   MemoryGrowthTracker memory_growth_tracker_;
 
   base::WeakPtrFactory<ChromeMetricsServiceClient> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeMetricsServiceClient);
 };
 
 #endif  // CHROME_BROWSER_METRICS_CHROME_METRICS_SERVICE_CLIENT_H_