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 <vector>
 
 #include "base/android/build_info.h"
 #include "base/android/jni_android.h"
+#include "base/android/jni_array.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 44 matching lines @@
   content_settings->GetDefaultContentSetting(content_settings_type, &source);
   HostContentSettingsMap::ProviderType provider =
       content_settings->GetProviderTypeFromSource(source);
   return provider >= HostContentSettingsMap::PREF_PROVIDER;
 }
 
 PrefService* GetPrefService() {
   return GetOriginalProfile()->GetPrefs();
 }
 
+void JavaByteArrayToString(JNIEnv* env,
+                           jbyteArray byte_array,
+                           std::string* out) {

[Alexei Svitkine (slow), 2015/11/03 18:34:03]

I suggest just making this return the std::string()

Then, your code actually can become simpler. One of the returns can change to
"return std::string();" and another to "return std::string(array_data.begin(),
array_data.end());"

It will simplify the code and likely won't introduce an extra copy since
compilers can optimize returned C++ objects (either via move ctors or in other
ways)/

[Alexander Agulenko, 2015/11/04 08:00:58]

Removed this function at all.

Done.

+  DCHECK(out);
+  if (!byte_array) {
+    out->clear();
+    return;
+  }
+  std::vector<uint8> array_data;
+  base::android::JavaByteArrayToByteVector(env, byte_array, &array_data);
+  std::string temp(array_data.begin(), array_data.end());
+  out->swap(temp);
+}
+
 }  // namespace
 
 // ----------------------------------------------------------------------------
 // Native JNI methods
 // ----------------------------------------------------------------------------
 
 static jboolean IsContentSettingManaged(JNIEnv* env,
                                         const JavaParamRef<jobject>& obj,
                                         int content_settings_type) {
   return IsContentSettingManaged(
@@ skipping 817 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
+void PrefServiceBridge::GetVariationsFirstRunSeed(
+    std::string* seed_data,
+    std::string* seed_signature,
+    std::string* seed_country) {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jbyteArray> j_seed_data =
+    Java_PrefServiceBridge_getVariationsFirstRunSeedData(

[Alexei Svitkine (slow), 2015/11/03 18:34:03]

Nit: Run "git cl format", since you have the wrong indent here.

[Alexander Agulenko, 2015/11/04 08:00:58]

Done.

+      env, GetApplicationContext());
+  ScopedJavaLocalRef<jstring> j_seed_signature =
+      Java_PrefServiceBridge_getVariationsFirstRunSeedSignature(
+        env, GetApplicationContext());
+  ScopedJavaLocalRef<jstring> j_seed_country =
+      Java_PrefServiceBridge_getVariationsFirstRunSeedCountry(
+        env, GetApplicationContext());
+  JavaByteArrayToString(env, j_seed_data.obj(), seed_data);
+  *seed_signature = ConvertJavaStringToUTF8(j_seed_signature);
+  *seed_country = ConvertJavaStringToUTF8(j_seed_country);
+}