Make the launch params the default client behavior for UMA 3g

components/metrics/metrics_service.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.
 
 //------------------------------------------------------------------------------
 // Description of the life cycle of a instance of MetricsService.
 //
 //  OVERVIEW
 //
 // A MetricsService instance is typically created at application startup.  It is
@@ skipping 182 matching lines @@
 
 // If an upload fails, and the transmission was over this byte count, then we
 // will discard the log, and not try to retransmit it.  We also don't persist
 // the log to the prefs for transmission during the next chrome session if this
 // limit is exceeded.
 const size_t kUploadLogAvoidRetransmitSize = 100 * 1024;
 
 // Interval, in minutes, between state saves.
 const int kSaveStateIntervalMinutes = 5;
 
+// Default sampling rate for UMA log uploads
+const int kDefaultSamplingProbability = 100;
+
 enum ResponseStatus {
   UNKNOWN_FAILURE,
   SUCCESS,
   BAD_REQUEST,  // Invalid syntax or log too large.
   NO_RESPONSE,
   NUM_RESPONSE_STATUSES
 };
 
 ResponseStatus ResponseCodeToStatus(int response_code) {
   switch (response_code) {
@@ skipping 15 matching lines @@
   local_state->SetInteger(prefs::kStabilityExecutionPhase,
                           MetricsService::SHUTDOWN_COMPLETE);
   // Start writing right away (write happens on a different thread).
   local_state->CommitPendingWrite();
 }
 #endif  // defined(OS_ANDROID) || defined(OS_IOS)
 
 // Determines if current log should be sent based on sampling rate. Returns true
 // if the sampling rate is not set.
 bool ShouldUploadLog() {
+  std::string experiment_group =
+      base::FieldTrialList::FindFullName("UMA_EnableCellularLogUpload");
+  if (experiment_group.empty())
+    return true;
+
   std::string probability_str = variations::GetVariationParamValue(
       "UMA_EnableCellularLogUpload", "Sample_Probability");
+  int probability;
   if (probability_str.empty())
-    return true;
+    probability = kDefaultSamplingProbability;

[Alexei Svitkine (slow), 2016/05/13 20:21:09]

I think we discussed offline that we could just remove this.

i.e. since we're not planning to use this sampling mechanism anymore, just get
rid of the code for it.

[gayane -on leave until 09-2017, 2016/05/13 20:43:00]

Done.

 
-  int probability;
   // In case specified sampling rate is invalid.
   if (!base::StringToInt(probability_str, &probability))
     return true;
   return base::RandInt(1, 100) <= probability;
 }
 
 }  // namespace
 
 // static
 MetricsService::ShutdownCleanliness MetricsService::clean_shutdown_status_ =
@@ skipping 937 matching lines @@
                  base::Time::Now().ToTimeT());
 }
 
 void MetricsService::SkipAndDiscardUpload() {
   log_manager_.DiscardStagedLog();
   scheduler_->UploadCancelled();
   log_upload_in_progress_ = false;
 }
 
 }  // namespace metrics