Activate the VariationsService for ChromeOS and ensure that it does not ping the server until the E…

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/base64.h"
 #include "base/build_time.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
-#include "base/metrics/histogram.h"
 #include "base/version.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/metrics/proto/trials_seed.pb.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/metrics/variations/variations_util.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/url_fetcher.h"
 #include "googleurl/src/gurl.h"
@@ skipping 68 matching lines @@
   GURL url_as_gurl = GURL(server_url);
   DCHECK(url_as_gurl.is_valid());
   return url_as_gurl;
 }
 
 }  // namespace
 
 VariationsService::VariationsService()
     : variations_server_url_(GetVariationsServerURL()),
       create_trials_from_seed_called_(false),
-      was_offline_during_last_request_attempt_(false) {
-  net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
+      resource_request_allowed_notifier_(
+          new ResourceRequestAllowedNotifier) {
+  resource_request_allowed_notifier_->Init(this);
+}
+
+VariationsService::VariationsService(ResourceRequestAllowedNotifier* notifier)
+    : variations_server_url_(GetVariationsServerURL()),
+      create_trials_from_seed_called_(false),
+      resource_request_allowed_notifier_(notifier) {
+  resource_request_allowed_notifier_->Init(this);
 }
 
 VariationsService::~VariationsService() {
-  net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
 }
 
 bool VariationsService::CreateTrialsFromSeed(PrefService* local_prefs) {
   create_trials_from_seed_called_ = true;
 
   TrialsSeed seed;
   if (!LoadTrialsSeedFromPref(local_prefs, &seed))
     return false;
 
   const int64 date_value = local_prefs->GetInt64(prefs::kVariationsSeedDate);
@@ skipping 28 matching lines @@
   FetchVariationsSeed();
 
   // Repeat this periodically.
   timer_.Start(FROM_HERE, base::TimeDelta::FromHours(kSeedFetchPeriodHours),
                this, &VariationsService::FetchVariationsSeed);
 }
 
 void VariationsService::FetchVariationsSeed() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
-  was_offline_during_last_request_attempt_ =
-      net::NetworkChangeNotifier::IsOffline();
-  UMA_HISTOGRAM_BOOLEAN("Variations.NetworkAvailability",
-                        !was_offline_during_last_request_attempt_);
-  if (was_offline_during_last_request_attempt_) {
-    DVLOG(1) << "Network was offline.";
+  if (!resource_request_allowed_notifier_->ResourceRequestsAllowed()) {
+    DVLOG(1) << "Resource requests were not allowed. Waiting for notification.";
     return;
   }
 
+  DoActualFetch();
+}
+
+// static
+void VariationsService::RegisterPrefs(PrefService* prefs) {
+  prefs->RegisterStringPref(prefs::kVariationsSeed, std::string());
+  prefs->RegisterInt64Pref(prefs::kVariationsSeedDate,
+                           base::Time().ToInternalValue());
+}
+
+ResourceRequestAllowedNotifier*
+VariationsService::GetResourceRequestAllowedNotifierForTesting() {

[Alexei Svitkine (slow), 2012/09/20 21:39:03]

Nit: Indent 4.

[SteveT, 2012/09/21 15:16:17]

Removed.

+  return resource_request_allowed_notifier_.get();
+}
+
+void VariationsService::SetCreateTrialsFromSeedCalledForTesting(bool called) {
+  create_trials_from_seed_called_ = called;
+}
+
+void VariationsService::DoActualFetch() {
   pending_seed_request_.reset(net::URLFetcher::Create(
       variations_server_url_, net::URLFetcher::GET, this));
   pending_seed_request_->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                                       net::LOAD_DO_NOT_SAVE_COOKIES);
   pending_seed_request_->SetRequestContext(
       g_browser_process->system_request_context());
   pending_seed_request_->SetMaxRetries(kMaxRetrySeedFetch);
   if (!variations_serial_number_.empty()) {
     pending_seed_request_->AddExtraRequestHeader("If-Match:" +
                                                  variations_serial_number_);
   }
   pending_seed_request_->Start();
 }
 
-void VariationsService::SetWasOfflineDuringLastRequestAttemptForTesting(
-    bool offline) {
-  was_offline_during_last_request_attempt_ = offline;
-}
-
-// static
-void VariationsService::RegisterPrefs(PrefService* prefs) {
-  prefs->RegisterStringPref(prefs::kVariationsSeed, std::string());
-  prefs->RegisterInt64Pref(prefs::kVariationsSeedDate,
-                           base::Time().ToInternalValue());
-}
-
 void VariationsService::OnURLFetchComplete(const net::URLFetcher* source) {
   DCHECK_EQ(pending_seed_request_.get(), source);
   // The fetcher will be deleted when the request is handled.
   scoped_ptr<const net::URLFetcher> request(
       pending_seed_request_.release());
   if (request->GetStatus().status() != net::URLRequestStatus::SUCCESS) {
     DVLOG(1) << "Variations server request failed.";
     return;
   }
 
   if (request->GetResponseCode() != 200) {
     DVLOG(1) << "Variations server request returned non-200 response code: "
              << request->GetResponseCode();
     return;
   }
 
   std::string seed_data;
   bool success = request->GetResponseAsString(&seed_data);
   DCHECK(success);
 
   base::Time response_date;
   success = request->GetResponseHeaders()->GetDateValue(&response_date);
   DCHECK(success || response_date.is_null());
 
   StoreSeedData(seed_data, response_date, g_browser_process->local_state());
 }
 
-void VariationsService::OnConnectionTypeChanged(
-    net::NetworkChangeNotifier::ConnectionType type) {
-  // If the connection type is back online, start a request if the last request
-  // failed due to being offline.
-  if (was_offline_during_last_request_attempt_ &&
-      type != net::NetworkChangeNotifier::CONNECTION_NONE) {
-    VLOG(1) << "Retrying fetch due to network reconnect.";
-    FetchVariationsSeed();
-
-    // Since FetchVariationsSeed was explicitly called here, reset the timer to
-    // avoid retrying for a full period.
-    // net::NetworkChangeNotifier::IsOffline may be inconsistent with |type|, so
-    // we check if FetchVariationsSeed set
-    // |was_offline_during_last_request_attempt_| to true before we reset the
-    // timer.
-    if (!was_offline_during_last_request_attempt_ && timer_.IsRunning())
-      timer_.Reset();
-  }
+void VariationsService::OnResourceRequestsAllowed() {
+  // Note that this only attempts to fetch the seed at most once per period
+  // (kSeedFetchPeriodHours). This works because
+  // |resource_request_allowed_notifier_| only calls this method if an
+  // attempt was made earlier that fails (which implies that the period had
+  // elapsed). After a successful attempt is made, the notifier will know not
+  // to call this method again until another failed attempt occurs.
+  DVLOG(1) << "Retrying fetch.";
+  FetchVariationsSeed();
+  if (timer_.IsRunning())
+    timer_.Reset();
 }
 
 bool VariationsService::StoreSeedData(const std::string& seed_data,
                                       const base::Time& seed_date,
                                       PrefService* local_prefs) {
   // Only store the seed data if it parses correctly.
   TrialsSeed seed;
   if (!seed.ParseFromString(seed_data)) {
     VLOG(1) << "Variations Seed data from server is not in valid proto format, "
             << "rejecting the seed.";
@@ skipping 248 matching lines @@
                                       variation_id);
     }
   }
 
   trial->SetForced();
   if (IsStudyExpired(study, reference_date))
     trial->Disable();
 }
 
 }  // namespace chrome_variations