Expose a method in VariationsService to trigger a seed fetch.

chrome/browser/metrics/variations/variations_service.cc

 // Copyright (c) 2012 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 "chrome/browser/metrics/variations/variations_service.h"
 
 #include <set>
 
 #include "base/build_time.h"
 #include "base/command_line.h"
@@ skipping 239 matching lines @@
   // Note that the act of instantiating the scheduler will start the fetch, if
   // the scheduler deems appropriate. Using Unretained is fine here since the
   // lifespan of request_scheduler_ is guaranteed to be shorter than that of
   // this service.
   request_scheduler_.reset(VariationsRequestScheduler::Create(
       base::Bind(&VariationsService::FetchVariationsSeed,
           base::Unretained(this)), local_state_));
   request_scheduler_->Start();
 }
 
+// TODO(rkaplow): Handle this and the similar event in metrics_service by
+// observing an 'OnAppEnterForeground' event instead of requiring the frontend
+// code to notify each service individually.

[Alexei Svitkine (slow), 2014/02/13 16:13:08]

My previous comment meant to emphasize that in the refactoring, this should
become a detail of VariationsRequestSchedulerMobile, and not known to
VariationsService directly. Can you expand the TODO to mention this?

[rkaplow, 2014/02/13 16:55:59]

Done.

+void VariationsService::OnAppEnterForeground() {
+  request_scheduler_->ScheduleFetch();
+}
+
 // static
 GURL VariationsService::GetVariationsServerURL(PrefService* local_state) {
   std::string server_url_string(CommandLine::ForCurrentProcess()->
       GetSwitchValueASCII(switches::kVariationsServerURL));
   if (server_url_string.empty())
     server_url_string = kDefaultVariationsServerURL;
   GURL server_url = GURL(server_url_string);
 
   const std::string restrict_param = GetRestrictParameterPref(local_state);
   if (!restrict_param.empty()) {
@@ skipping 98 matching lines @@
   if (request_status.status() != net::URLRequestStatus::SUCCESS) {
     UMA_HISTOGRAM_SPARSE_SLOWLY("Variations.FailedRequestErrorCode",
                                 -request_status.error());
     DVLOG(1) << "Variations server request failed with error: "
              << request_status.error() << ": "
              << net::ErrorToString(request_status.error());
     // It's common for the very first fetch attempt to fail (e.g. the network
     // may not yet be available). In such a case, try again soon, rather than
     // waiting the full time interval.
     if (is_first_request)
-      request_scheduler_->ScheduleFetchShortly();
+      request_scheduler_->ForceFetch();
     return;
   }
 
   // Log the response code.
   const int response_code = request->GetResponseCode();
   UMA_HISTOGRAM_SPARSE_SLOWLY("Variations.SeedFetchResponseCode",
                               response_code);
 
   const base::TimeDelta latency =
       base::TimeTicks::Now() - last_request_started_time_;
@@ skipping 59 matching lines @@
 
 void VariationsService::RecordLastFetchTime() {
   // local_state_ is NULL in tests, so check it first.
   if (local_state_) {
     local_state_->SetInt64(prefs::kVariationsLastFetchTime,
                            base::Time::Now().ToInternalValue());
   }
 }
 
 }  // namespace chrome_variations