Variations seed is pulled from the Java application on the first launch of Chrome

chrome/browser/android/preferences/pref_service_bridge.cc

 // Copyright 2014 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/android/preferences/pref_service_bridge.h"
 
 #include <jni.h>
 
 #include "base/android/build_info.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/jni_weak_ref.h"
+#include "base/base64.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browsing_data/browsing_data_helper.h"
 #include "chrome/browser/browsing_data/browsing_data_remover.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/net/prediction_options.h"
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/translate/chrome_translate_client.h"
 #include "chrome/browser/ui/android/android_about_app_info.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/grit/locale_settings.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
 #include "components/content_settings/core/common/pref_names.h"
 #include "components/metrics/metrics_pref_names.h"
 #include "components/password_manager/core/common/password_manager_pref_names.h"
 #include "components/signin/core/common/signin_pref_names.h"
 #include "components/translate/core/browser/translate_prefs.h"
 #include "components/translate/core/common/translate_pref_names.h"
+#include "components/variations/pref_names.h"
 #include "components/version_info/version_info.h"
 #include "components/web_resource/web_resource_pref_names.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/user_metrics.h"
 #include "jni/PrefServiceBridge_jni.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using base::android::AttachCurrentThread;
 using base::android::CheckException;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF8ToJavaString;
+using base::android::GetApplicationContext;
 using base::android::ScopedJavaLocalRef;
 using base::android::ScopedJavaGlobalRef;
 using content::BrowserThread;
 
 namespace {
 
 enum NetworkPredictionOptions {
   NETWORK_PREDICTION_ALWAYS,
   NETWORK_PREDICTION_WIFI_ONLY,
   NETWORK_PREDICTION_NEVER,
@@ skipping 881 matching lines @@
     ContentSettingsType content_type) {
   JNIEnv* env = AttachCurrentThread();
   base::android::ScopedJavaLocalRef<jstring> android_permission =
       Java_PrefServiceBridge_getAndroidPermissionForContentSetting(
           env, content_type);
   if (android_permission.is_null())
     return std::string();
 
   return ConvertJavaStringToUTF8(android_permission);
 }
+
+// static
+std::string PrefServiceBridge::PullVariationsSeedPref(

[Alexei Svitkine (slow), 2015/10/28 15:16:38]

Instead of being able to pass arbitrary pref names, I suggest making this
function have out-params for the specific fields it needs.

Specifically, it will look like:

bool PrefServiceBridge::GetFirstRunVariationSeedValues(
    std::string* seed_content,
    std::string* seed_signature,
    std::string* seed_country) {
  ...
}

Then, the calling code from VariationsSeedStore just needs to do a single call
to get all the values and doesn't need to know the internal pref names used on
the Java side to get this info.

[Alexander Agulenko, 2015/10/28 23:05:09]

Done.

+  const std::string& prefName) {
+  if (prefName == variations::prefs::kVariationsSeed) {

[Alexei Svitkine (slow), 2015/10/28 15:16:38]

Nit: No {}'s

[Alexander Agulenko, 2015/10/28 23:05:09]

Done.

+    return PullRawVariationsSeed();
+  }
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jstring> j_pref_name = ConvertUTF8ToJavaString(env,
+                                                                    prefName);
+  base::android::ScopedJavaLocalRef<jstring> pref_data =
+      Java_PrefServiceBridge_getVariationsSeedPref(env, GetApplicationContext(), 
+                                                   j_pref_name.obj());
+  return ConvertJavaStringToUTF8(pref_data);
+}
+
+// static
+std::string PrefServiceBridge::PullRawVariationsSeed() {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jbyteArray> array = 
+    Java_PrefServiceBridge_getRawVariationsSeed(env, GetApplicationContext());
+  if (array.is_null()) {
+    return std::string();
+  }
+  int array_length = env->GetArrayLength(array.obj());
+  /* std::string seed;

[Steven Holte, 2015/10/28 01:00:18]

Looks like unfinished code?

[Alexander Agulenko, 2015/10/28 23:05:09]

Done.

[Alexander Agulenko, 2015/10/28 23:05:09]

Yes, this piece of code has been changed in Patch 2.

+  seed.resize(array_length);
+  env->GetByteArrayRegion(array.obj(), 0, array_length,
+                          reinterpret_cast<jbyte*>(&(seed[0])));
+  return seed; */
+  char* buf = new char[array_length];
+  env->GetByteArrayRegion(array.obj(), 0, array_length,
+    reinterpret_cast<jbyte*>(buf));
+  std::string seed(buf, buf + array_length);
+  delete[] buf;
+  return seed;
+}