Added enhanced bookmarks extension as an external component extension

chrome/browser/extensions/external_component_loader.cc

 // Copyright (c) 2013 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/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() {}
 
+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");

[Yaron, 2013/11/21 23:47:01]

Actually, in thinking about this, I don't know if this really addresses your
concern about using a command line flag to force an experiment which downloads
an extension. There's another command line flag which allows you to add your
experiment to all whitelists so this doesn't really help. I think the first step
is to see if we need to worry or if we have sufficient control over finch
experiments to see if this is an actual issue

[yefimt, 2013/11/21 23:50:54]

Command line flag should work, it will get parameters (like id) from finch, the
only problem I found that chrome always need to be run with flag in command
line, not just one time. Removing flag from command line will remove extension.

On 2013/11/21 23:47:01, Yaron wrote:

+  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",
+                      extension_urls::GetWebstoreUpdateUrl().spec());
+  }
   LoadFinished();
 }
 
 }  // namespace extensions