Add UMA stats to track whitelist download latency.

components/autofill/browser/autocheckout/whitelist_manager.cc

 // Copyright (c) 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 "components/autofill/browser/autocheckout/whitelist_manager.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string_util.h"
@@ skipping 59 matching lines @@
 void WhitelistManager::StartDownloadTimer(size_t interval_seconds) {
   download_timer_.Start(FROM_HERE,
                         base::TimeDelta::FromSeconds(interval_seconds),
                         this,
                         &WhitelistManager::TriggerDownload);
 }
 
 void WhitelistManager::TriggerDownload() {
   callback_is_pending_ = true;
 
+  request_started_timestamp_ = base::Time::Now();
+
   request_.reset(net::URLFetcher::Create(
       0, GURL(kWhitelistUrl), net::URLFetcher::GET, this));
   request_->SetRequestContext(context_getter_);
   request_->SetAutomaticallyRetryOn5xx(false);
   request_->SetLoadFlags(net::LOAD_DO_NOT_SAVE_COOKIES |
                          net::LOAD_DO_NOT_SEND_COOKIES);
   request_->Start();
 }
 
 void WhitelistManager::StopDownloadTimer() {
   download_timer_.Stop();
   callback_is_pending_ = false;
 }
 
 void WhitelistManager::OnURLFetchComplete(
     const net::URLFetcher* source) {
   DCHECK(callback_is_pending_);
   callback_is_pending_ = false;
   scoped_ptr<net::URLFetcher> old_request = request_.Pass();
   DCHECK_EQ(source, old_request.get());
 
   if (source->GetResponseCode() == net::HTTP_OK) {
+    GetMetricLogger().LogAutocheckoutWhitelistDownloadDuration(
+        base::Time::Now() - request_started_timestamp_,
+        AutofillMetrics::WHITELIST_DOWNLOAD_SUCCEEDED);
     std::string data;
     source->GetResponseAsString(&data);
     BuildWhitelist(data);
+  } else {
+    GetMetricLogger().LogAutocheckoutWhitelistDownloadDuration(
+        base::Time::Now() - request_started_timestamp_,
+        AutofillMetrics::WHITELIST_DOWNLOAD_FAILED);

[Ilya Sherman, 2013/04/17 00:18:01]

nit: Would be nice to move most of this code out of the if/else, and just have a
variable that is set to either AutofillMetrics::WHITELIST_DOWNLOAD_SUCCEEDED or
AutofillMetrics::WHITELIST_DOWNLOAD_FAILED.

[benquan, 2013/04/17 01:51:30]

In the If block, I want to track UMA before calling BuildWhitelist(data), so
that we do not include parsing time. If we want to move the code out of if/else,
it should be before the "if" statement, it will require performing another
(source->GetResponseCode() == net::HTTP_OK) test, it won't be much nicer. I will
leave it as is for now, please let me know if think otherwise.

[Ilya Sherman, 2013/04/17 05:01:48]

You can compute the duration outside of the if/else as well.  IMO that's still
cleaner, but it's not critical to change this.

[benquan, 2013/04/17 05:48:18]

Done.

   }
 
   ScheduleDownload(kDownloadIntervalSeconds);
 }
 
 std::string WhitelistManager::GetMatchedURLPrefix(const GURL& url) const {
   if (!experimental_form_filling_enabled_ || url.is_empty())
     return std::string();
 
   for (std::vector<std::string>::const_iterator it = url_prefixes_.begin();
@@ skipping 25 matching lines @@
       // Chrome can ignore them and continue to work.
       if (!fields[0].empty())
         new_url_prefixes.push_back(fields[0]);
     }
   }
   url_prefixes_ = new_url_prefixes;
 }
 
 }  // namespace autocheckout
 }  // namespace autofill