MD Settings: clarify "controlled by" logic

chrome/browser/extensions/api/settings_private/prefs_util.cc

Index: chrome/browser/extensions/api/settings_private/prefs_util.cc
diff --git a/chrome/browser/extensions/api/settings_private/prefs_util.cc b/chrome/browser/extensions/api/settings_private/prefs_util.cc
index bda474d01b7c1d8ccbf94ba8feff4ff3a6981724..fd7204e11bfd4b537c455630d05ff0f94c6fe851 100644
--- a/chrome/browser/extensions/api/settings_private/prefs_util.cc
+++ b/chrome/browser/extensions/api/settings_private/prefs_util.cc
@@ -7,6 +7,7 @@
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/chrome_extension_function.h"
+#include "chrome/browser/extensions/settings_api_helpers.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/pref_names.h"
 #include "components/autofill/core/common/autofill_pref_names.h"
@@ -19,6 +20,7 @@
 #include "components/proxy_config/proxy_config_pref_names.h"
 #include "components/proxy_config/proxy_config_pref_names.h"
 #include "components/safe_browsing_db/safe_browsing_prefs.h"
+#include "components/search_engines/search_engines_pref_names.h"
 #include "components/spellcheck/browser/pref_names.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/translate/core/common/translate_pref_names.h"
@@ -27,6 +29,7 @@
 #include "extensions/browser/extension_pref_value_map_factory.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension.h"
+#include "extensions/common/manifest.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/ownership/owner_settings_service_chromeos.h"
@@ -456,24 +459,22 @@ std::unique_ptr<settings_private::PrefObject> PrefsUtil::GetPref(
   }
 #endif
 
-  if (pref && pref->IsExtensionControlled()) {
-    std::string extension_id =
-        ExtensionPrefValueMapFactory::GetForBrowserContext(profile_)
-            ->GetExtensionControllingPref(pref->name());
-    const Extension* extension = ExtensionRegistry::Get(profile_)->
-        GetExtensionById(extension_id, ExtensionRegistry::ENABLED);
-    if (extension) {
-      pref_object->policy_source =
-          settings_private::PolicySource::POLICY_SOURCE_EXTENSION;
-      pref_object->policy_enforcement =
-          settings_private::PolicyEnforcement::POLICY_ENFORCEMENT_ENFORCED;
-      pref_object->extension_id.reset(new std::string(extension_id));
-      pref_object->policy_source_name.reset(new std::string(extension->name()));
-      return pref_object;
-    }
+  const Extension* extension = GetExtensionControllingPref(name);
+  if (extension) {
+    bool force_installed = Manifest::IsPolicyLocation(extension->location());
+    pref_object->read_only.reset(new bool(force_installed));
+    pref_object->policy_source =
+        settings_private::PolicySource::POLICY_SOURCE_EXTENSION;
+    pref_object->policy_enforcement =
+        settings_private::PolicyEnforcement::POLICY_ENFORCEMENT_ENFORCED;
+    pref_object->extension_id.reset(new std::string(extension->id()));
+    pref_object->policy_source_name.reset(new std::string(extension->name()));
+    return pref_object;
   }
+
   if (pref && (!pref->IsUserModifiable() || IsPrefSupervisorControlled(name))) {
     // TODO(stevenjb): Investigate whether either of these should be badged.
+    // TODO(dbeam): where is this ever used?
     pref_object->read_only.reset(new bool(true));
     return pref_object;
   }
@@ -699,4 +700,18 @@ bool PrefsUtil::IsCrosSetting(const std::string& pref_name) {
 #endif
 }
 
+const Extension* PrefsUtil::GetExtensionControllingPref(
+    const std::string& pref_name) {
+  if (pref_name == ::prefs::kHomePage)
+    return GetExtensionOverridingHomepage(profile_);
+  if (pref_name == ::prefs::kRestoreOnStartup)
+    return GetExtensionOverridingStartupPages(profile_);
+  // TODO(dbeam): add kDefaultSearchProviderEnabled to whitelist soon.
+  if (pref_name == ::prefs::kDefaultSearchProviderEnabled)
+    return GetExtensionOverridingSearchEngine(profile_);
+  if (pref_name == proxy_config::prefs::kProxy)
+    return GetExtensionOverridingProxy(profile_);
+  return nullptr;
+}
+
 }  // namespace extensions