Add various UMA histograms for measuring GCM crypto performance

components/gcm_driver/gcm_stats_recorder_impl.cc

 // 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.
 
 #include "components/gcm_driver/gcm_stats_recorder_impl.h"
 
 #include <deque>
 #include <vector>
 
 #include "base/format_macros.h"
@@ skipping 155 matching lines @@
   decryption_failure_activities_.clear();
 }
 
 void GCMStatsRecorderImpl::NotifyActivityRecorded() {
   if (delegate_)
     delegate_->OnActivityRecorded();
 }
 
 void GCMStatsRecorderImpl::RecordDecryptionFailure(
     const std::string& app_id,
-    GCMEncryptionProvider::DecryptionFailure reason) {
+    GCMEncryptionProvider::DecryptionResult result) {
+  DCHECK_NE(result, GCMEncryptionProvider::DECRYPTION_RESULT_UNENCRYPTED);
+  DCHECK_NE(result, GCMEncryptionProvider::DECRYPTION_RESULT_DECRYPTED);
   if (!is_recording_)
     return;
 
   DecryptionFailureActivity data;
   DecryptionFailureActivity* inserted_data = InsertCircularBuffer(
       &decryption_failure_activities_, data);
   inserted_data->app_id = app_id;
   inserted_data->details =
-      GCMEncryptionProvider::ToDecryptionFailureDetailsString(reason);
+      GCMEncryptionProvider::ToDecryptionResultDetailsString(result);
 
   NotifyActivityRecorded();
 }
 
 void GCMStatsRecorderImpl::RecordCheckin(
     const std::string& event,
     const std::string& details) {
   CheckinActivity data;
   CheckinActivity* inserted_data = InsertCircularBuffer(
       &checkin_activities_, data);
@@ skipping 339 matching lines @@
     const std::string& receiver_id,
     const std::string& message_id) {
   UMA_HISTOGRAM_COUNTS("GCM.IncomingSendErrors", 1);
   if (!is_recording_)
     return;
   RecordSending(app_id, receiver_id, message_id, "Received 'send error' msg",
                 std::string());
 }
 
 }  // namespace gcm