Hard coded finch config for Popular site

components/ntp_tiles/field_trial.cc

Index: components/ntp_tiles/field_trial.cc
diff --git a/components/ntp_tiles/field_trial.cc b/components/ntp_tiles/field_trial.cc
new file mode 100644
index 0000000000000000000000000000000000000000..39f4b7252ea18f0656bac20126e33b999d796560
--- /dev/null
+++ b/components/ntp_tiles/field_trial.cc
@@ -0,0 +1,96 @@
+// Copyright 2016 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 "base/metrics/field_trial.h"
+
+#if defined(OS_ANDROID)
+#include <jni.h>
+#endif
+
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
+#include "base/strings/string_util.h"
+#include "components/ntp_tiles/constants.h"
+#include "components/ntp_tiles/field_trial.h"
+#include "components/ntp_tiles/switches.h"
+
+#if defined(OS_ANDROID)
+#include "base/android/jni_android.h"
+#include "jni/MostVisitedSites_jni.h"
+#endif
+
+namespace {
+const char kPopularSiteDefaultGroup[] = "Default";
+const char kPopularSiteControlGroup[] = "Control";
+const char kPopularSiteEnabledGroup[] = "Enabled";
+const char kPopularSiteEnabledCommandLineSwitchGroup[] =
+    "EnabledWithCommandLineSwitch";
+const char kPopularSiteDisabledCommandLineSwitchGroup[] =
+    "DisabledWithCommandLineSwitch";
+}  // namespace
+
+namespace ntp_tiles {
+
+// On iOS it is not technically possible to prep the field trials on first
+// launch, the configuration file is downloaded too late. In order to run some
+// experiments that need to be active on first launch to be meaningful these
+// are hardcoded, but can be superceeded by a server side config on subsequent
+// launches.
+void SetUpFirstLaunchFieldTrial(bool is_stable_channel) {
+  // Check first if a server side config superceeded this experiment.
+  if (base::FieldTrialList::TrialExists(kPopularSitesFieldTrialName))
+    return;
+
+  // Stable channels will run with 10% probability.
+  // Non-stable channels will run with 50% probability.
+  const base::FieldTrial::Probability kTotalProbability = 100;
+  const base::FieldTrial::Probability kEnabledAndControlProbability =
+      is_stable_channel ? 10 : 50;
+
+  // Experiment enabled until March 15, 2017. By default, disabled.
+  scoped_refptr<base::FieldTrial> trial(
+      base::FieldTrialList::FactoryGetFieldTrial(
+          kPopularSitesFieldTrialName, kTotalProbability,
+          kPopularSiteDefaultGroup, 2017, 3, 15,  // Mar 15, 2017
+          base::FieldTrial::ONE_TIME_RANDOMIZED, nullptr));
+
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(ntp_tiles::switches::kEnableNTPPopularSites)) {
+    trial->AppendGroup(kPopularSiteEnabledCommandLineSwitchGroup,
+                       kTotalProbability);
+  } else if (command_line->HasSwitch(
+                 ntp_tiles::switches::kDisableNTPPopularSites)) {
+    trial->AppendGroup(kPopularSiteDisabledCommandLineSwitchGroup,
+                       kTotalProbability);
+  } else {
+    trial->AppendGroup(kPopularSiteControlGroup, kEnabledAndControlProbability);
+    trial->AppendGroup(kPopularSiteEnabledGroup, kEnabledAndControlProbability);
+  }
+}
+
+bool ShouldShowPopularSites() {
+  // Note: It's important to query the field trial state first, to ensure that
+  // UMA reports the correct group.
+  const std::string group_name =
+      base::FieldTrialList::FindFullName(kPopularSitesFieldTrialName);
+
+  base::CommandLine* cmd_line = base::CommandLine::ForCurrentProcess();
+  if (cmd_line->HasSwitch(switches::kDisableNTPPopularSites))
+    return false;
+
+  if (cmd_line->HasSwitch(switches::kEnableNTPPopularSites))
+    return true;
+
+#if defined(OS_ANDROID)
+  if (Java_MostVisitedSites_isPopularSitesForceEnabled(
+          base::android::AttachCurrentThread())) {
+    return true;
+  }
+#endif
+
+  return base::StartsWith(group_name, "Enabled",
+                          base::CompareCase::INSENSITIVE_ASCII);
+}
+
+}  // namespace ntp_tiles