Add histograms to entire MergeSession flow.

google_apis/gaia/oauth2_token_service.cc

 // Copyright 2013 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 "google_apis/gaia/oauth2_token_service.h"
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "google_apis/gaia/gaia_urls.h"
 #include "google_apis/gaia/google_service_auth_error.h"
 #include "google_apis/gaia/oauth2_access_token_fetcher_impl.h"
 #include "net/url_request/url_request_context_getter.h"
 
@@ skipping 262 matching lines @@
 }
 
 void OAuth2TokenService::Fetcher::OnGetTokenFailure(
     const GoogleServiceAuthError& error) {
   fetcher_.reset();
 
   if (ShouldRetry(error) && retry_number_ < max_fetch_retry_num_) {
     base::TimeDelta backoff = base::TimeDelta::FromMilliseconds(
         ComputeExponentialBackOffMilliseconds(retry_number_));
     ++retry_number_;
+    UMA_HISTOGRAM_ENUMERATION("Signin.OAuth2TokenGetRetry",
+        error.state(), GoogleServiceAuthError::NUM_STATES);
     retry_timer_.Stop();
     retry_timer_.Start(FROM_HERE,
                        backoff,
                        this,
                        &OAuth2TokenService::Fetcher::Start);
     return;
   }
 
+  UMA_HISTOGRAM_ENUMERATION("Signin.OAuth2TokenGetFailure",
+      error.state(), GoogleServiceAuthError::NUM_STATES);
   error_ = error;
   InformWaitingRequestsAndDelete();
 }
 
 // Returns an exponential backoff in milliseconds including randomness less than
 // 1000 ms when retrying fetching an OAuth2 access token.
 int64 OAuth2TokenService::Fetcher::ComputeExponentialBackOffMilliseconds(
     int retry_num) {
   DCHECK(retry_num < max_fetch_retry_num_);
   int64 exponential_backoff_in_seconds = 1 << retry_num;
@@ skipping 530 matching lines @@
     const std::string& account_id,
     const ScopeSet& scopes) const {
   PendingFetcherMap::const_iterator iter = pending_fetchers_.find(
       OAuth2TokenService::RequestParameters(
           client_id,
           account_id,
           scopes));
   return iter == pending_fetchers_.end() ?
              0 : iter->second->GetWaitingRequestCount();
 }