[Merge-57] arc: Logging ARC data removal reasons

chrome/browser/chromeos/arc/arc_optin_uma.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 CHROME_BROWSER_CHROMEOS_ARC_ARC_OPTIN_UMA_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_ARC_OPTIN_UMA_H_
 
+#include <ostream>
+
 namespace base {
 class TimeDelta;
 }
 
 namespace arc {
 
 // These enums are used to define the buckets for an enumerated UMA histogram
 // and need to be synced with histograms.xml
 enum class OptInActionType : int {
   OPTED_OUT = 0,               // Arc was opted out by user.
@@ skipping 95 matching lines @@
 
 void UpdateOptInActionUMA(OptInActionType type);
 void UpdateOptInCancelUMA(OptInCancelReason reason);
 void UpdateEnabledStateUMA(bool enabled);
 void UpdateProvisioningResultUMA(ProvisioningResult result, bool managed);
 void UpdateProvisioningTiming(const base::TimeDelta& elapsed_time,
                               bool success,
                               bool managed);
 void UpdateSilentAuthCodeUMA(OptInSilentAuthCode state);
 
+// Outputs the stringified |result| to |os|. This is only for logging purposes.
+std::ostream& operator<<(std::ostream& os, const ProvisioningResult& result);
+
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_OPTIN_UMA_H_