Make extensions developer mode adhere to policy

chrome/browser/policy/configuration_policy_handler_list_factory.cc

Index: chrome/browser/policy/configuration_policy_handler_list_factory.cc
diff --git a/chrome/browser/policy/configuration_policy_handler_list_factory.cc b/chrome/browser/policy/configuration_policy_handler_list_factory.cc
index 894c04a548d845cb91eff2265a28fc5c701bbb6c..3695f59e3277f6258c0ed8bda1bf527b3e9f8bca 100644
--- a/chrome/browser/policy/configuration_policy_handler_list_factory.cc
+++ b/chrome/browser/policy/configuration_policy_handler_list_factory.cc
@@ -708,6 +708,33 @@ void GetExtensionAllowedTypesMap(
                             new base::FundamentalValue(entry.manifest_type))));
   }
 }
+
+// Piggy-back kDeveloperToolsDisabled set to true to also force-disable
+// kExtensionsUIDeveloperMode.
+class DevToolsExtensionsUIPolicyHandler : public TypeCheckingPolicyHandler {
+ public:
+  DevToolsExtensionsUIPolicyHandler()
+      : TypeCheckingPolicyHandler(key::kDeveloperToolsDisabled,
+                                  base::Value::TYPE_BOOLEAN) {}
+  ~DevToolsExtensionsUIPolicyHandler() override {}
+
+  // ConfigurationPolicyHandler implementation:
+  void ApplyPolicySettings(const PolicyMap& policies,
+                           PrefValueMap* prefs) override {
+    const base::Value* value = policies.GetValue(policy_name());
+    bool developerToolsDisabled;
+    if (value &&
+        value->GetAsBoolean(&developerToolsDisabled) &&
+        developerToolsDisabled) {
+      prefs->SetValue(
+          prefs::kExtensionsUIDeveloperMode,
+          base::MakeUnique<base::FundamentalValue>(false));
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DevToolsExtensionsUIPolicyHandler);
+};
 #endif
 
 void GetDeprecatedFeaturesMap(
@@ -793,6 +820,8 @@ std::unique_ptr<ConfigurationPolicyHandlerList> BuildHandlerList(
   handlers->AddHandler(
       base::MakeUnique<extensions::ExtensionSettingsPolicyHandler>(
           chrome_schema));
+  handlers->AddHandler(
+      base::MakeUnique<DevToolsExtensionsUIPolicyHandler>());
 #endif
 
 #if !defined(OS_CHROMEOS) && !defined(OS_ANDROID)