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..660763a49336b9440d6fb758a3ccde4422e8f933 100644
--- a/chrome/browser/extensions/external_component_loader.cc
+++ b/chrome/browser/extensions/external_component_loader.cc
@@ -4,20 +4,52 @@
 
 #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();
 }