MD Settings: implement metrics reporting checkbox on desktop

chrome/browser/ui/webui/settings/metrics_reporting_handler.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 "chrome/browser/ui/webui/settings/metrics_reporting_handler.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/values.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/metrics/chrome_metrics_service_accessor.h"
+#include "chrome/browser/metrics/metrics_reporting_state.h"
+#include "components/metrics/metrics_pref_names.h"
+#include "components/prefs/pref_service.h"
+#include "content/public/browser/web_ui.h"
+#include "policy/policy_constants.h"
+
+namespace settings {
+
+MetricsReportingHandler::MetricsReportingHandler() {}
+MetricsReportingHandler::~MetricsReportingHandler() {}
+
+void MetricsReportingHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback("getMetricsReporting",
+      base::Bind(&MetricsReportingHandler::HandleGetMetricsReporting,
+                 base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("setMetricsReportingEnabled",
+      base::Bind(&MetricsReportingHandler::HandleSetMetricsReportingEnabled,
+                 base::Unretained(this)));
+}
+
+void MetricsReportingHandler::OnJavascriptAllowed() {
+  pref_member_.reset(new BooleanPrefMember);
+  pref_member_->Init(metrics::prefs::kMetricsReportingEnabled,
+                     g_browser_process->local_state(),
+                     base::Bind(&MetricsReportingHandler::OnPrefChanged,
+                                base::Unretained(this)));
+
+  policy_registrar_.reset(new policy::PolicyChangeRegistrar(
+      g_browser_process->policy_service(),
+      policy::PolicyNamespace(policy::POLICY_DOMAIN_CHROME, std::string())));
+  policy_registrar_->Observe(policy::key::kMetricsReportingEnabled,
+      base::Bind(&MetricsReportingHandler::OnPolicyChanged,
+                 base::Unretained(this)));
+}
+
+void MetricsReportingHandler::OnJavascriptDisallowed() {
+  pref_member_.reset();
+  policy_registrar_.reset();
+}
+
+void MetricsReportingHandler::HandleGetMetricsReporting(
+    const base::ListValue* args) {
+  AllowJavascript();
+  const base::Value* callback_id;
+  CHECK(args->Get(0, &callback_id));
+  ResolveJavascriptCallback(*callback_id, *CreateMetricsReportingDict());
+}
+
+std::unique_ptr<base::DictionaryValue>
+    MetricsReportingHandler::CreateMetricsReportingDict() {
+  std::unique_ptr<base::DictionaryValue> dict(new base::DictionaryValue);
+  dict->SetBoolean("enabled",
+      ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled());
+  dict->SetBoolean("managed", IsMetricsReportingPolicyManaged());
+  return dict;
+}
+
+void MetricsReportingHandler::HandleSetMetricsReportingEnabled(
+    const base::ListValue* args) {
+  if (IsMetricsReportingPolicyManaged()) {
+    NOTREACHED();
+    // NOTE: ChangeMetricsReportingState() already checks whether metrics
+    // reporting is managed by policy. Also, the UI really shouldn't be able to
+    // send this message when managed. However, in this specific case, there's a
+    // sane, graceful fallback so we might as well do that.
+    SendMetricsReportingChange();
+    return;
+  }
+
+  bool enabled;
+  CHECK(args->GetBoolean(0, &enabled));
+  ChangeMetricsReportingState(enabled);
+}
+
+void MetricsReportingHandler::OnPolicyChanged(const base::Value* previous,
+                                              const base::Value* current) {
+  SendMetricsReportingChange();
+}
+
+void MetricsReportingHandler::OnPrefChanged(const std::string& pref_name) {
+  DCHECK_EQ(metrics::prefs::kMetricsReportingEnabled, pref_name);
+  SendMetricsReportingChange();
+}
+
+void MetricsReportingHandler::SendMetricsReportingChange() {
+  CallJavascriptFunction(
+      "cr.webUIListenerCallback",
+      base::StringValue("metrics-reporting-change"),
+      *CreateMetricsReportingDict());
+}
+
+}  // namespace settings