[OBSOLETE] Reporting: Initial implementation.

net/reporting/reporting_controls.cc

+// Copyright 2016 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 "net/reporting/reporting_controls.h"
+
+#include <cstring>
+#include <string>
+
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
+#include "net/reporting/reporting_metrics.h"
+
+namespace net {
+
+namespace {
+
+const bool kDefaultEnabled = false;
+
+const char kFieldTrialName[] = "Reporting-Enable";
+const char kFieldTrialValuePrefix[] = "enable";
+
+}  // namespace
+
+bool GetReportingEnabled(const char* disable_switch_name,
+                         const char* enable_switch_name) {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (disable_switch_name && command_line->HasSwitch(disable_switch_name)) {
+    HistogramEnabledState(ENABLED_STATE_DISABLED_COMMAND_LINE);
+    return false;
+  }
+  if (enable_switch_name && command_line->HasSwitch(enable_switch_name)) {
+    HistogramEnabledState(ENABLED_STATE_ENABLED_COMMAND_LINE);
+    return true;
+  }
+
+  if (base::FieldTrialList::TrialExists(kFieldTrialName)) {
+    std::string value = base::FieldTrialList::FindFullName(kFieldTrialName);
+    bool enabled = !value.compare(0, strlen(kFieldTrialValuePrefix),
+                                  kFieldTrialValuePrefix);
+    if (enabled)
+      HistogramEnabledState(ENABLED_STATE_ENABLED_FIELD_TRIAL);
+    else
+      HistogramEnabledState(ENABLED_STATE_DISABLED_FIELD_TRIAL);
+    return enabled;
+  }
+
+  if (kDefaultEnabled)
+    HistogramEnabledState(ENABLED_STATE_ENABLED_DEFAULT);
+  else
+    HistogramEnabledState(ENABLED_STATE_DISABLED_DEFAULT);
+  return kDefaultEnabled;

[Ryan Sleevi, 2017/01/03 21:28:12]

As mentioned in the header, this all seems like something base::FeatureList is
meant to embody, and it would be good to know if that was intentionally avoided.

This will also hopefully eliminate the need for HistogramEnabledState(), since
such configs can be represented using the field trial config reporting already
used.

[Julia Tuttle, 2017/01/25 20:27:45]

Obsolete; I'm now using base::Feature.

+}
+
+}  // namespace net