Added enhanced bookmarks extension as an external component extension

chrome/browser/extensions/external_component_loader.cc

Index: chrome/browser/extensions/external_component_loader.cc
diff --git a/chrome/browser/extensions/external_component_loader.cc b/chrome/browser/extensions/external_component_loader.cc
index bec5d2f9e99b90529eaa13f90df9723e127d6370..6ccfec488c45f04a59bde31ab7db51f1e8ea2661 100644
--- a/chrome/browser/extensions/external_component_loader.cc
+++ b/chrome/browser/extensions/external_component_loader.cc
@@ -4,20 +4,53 @@
 
 #include "chrome/browser/extensions/external_component_loader.h"
 
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/values.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension_constants.h"
+#include "components/variations/variations_associated_data.h"
+#include "extensions/common/features/feature.h"
+#include "extensions/common/features/feature_provider.h"
 
 namespace extensions {
 
+const char kFieldTrialName[] = "EnhancedBookmarks";
+
 ExternalComponentLoader::ExternalComponentLoader() {}
 
 ExternalComponentLoader::~ExternalComponentLoader() {}
 
+// This function will be removed after experiment goes to all users or go away.
+bool ExternalComponentLoader::IsEnhancedBookmarksExperimentEnabled() {
+  const char kFieldTrialDefaultGroupName[] = "Default";
+  std::string field_trial_group_name =
+      base::FieldTrialList::FindFullName(kFieldTrialName);
+  if (field_trial_group_name.empty() ||
+      field_trial_group_name == kFieldTrialDefaultGroupName) {
+    return false;
+  }
+  std::string app_id =
+      chrome_variations::GetVariationParamValue(kFieldTrialName, "id");
+  FeatureProvider* feature_provider = FeatureProvider::GetPermissionFeatures();
+  Feature* feature = feature_provider->GetFeature("metricsPrivate");
+  return (feature && feature->IsIdInWhitelist(app_id));
+}
+
 void ExternalComponentLoader::StartLoading() {
   prefs_.reset(new base::DictionaryValue());
   std::string appId = extension_misc::kInAppPaymentsSupportAppId;
   prefs_->SetString(appId + ".external_update_url",
                     extension_urls::GetWebstoreUpdateUrl().spec());
+
+  if (IsEnhancedBookmarksExperimentEnabled() &&
+      (CommandLine::ForCurrentProcess()->
+          GetSwitchValueASCII(switches::kEnableEnhancedBookmarks) != "0")) {
+    std::string app_id =
+        chrome_variations::GetVariationParamValue(kFieldTrialName, "id");
+    prefs_->SetString(app_id + ".external_update_url",

[meacer, 2013/11/26 01:32:03]

Can we restrict the update url to Web Store for all external components in
addition to this? Since now external components aren't going to be listed in the
extensions page, it would be good if we can make sure they are only updated
through the Web Store, as a hardening mechanism.

+                      extension_urls::GetWebstoreUpdateUrl().spec());
+  }
   LoadFinished();
 }