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

chrome/browser/android/preferences/pref_service_bridge.cc

Index: chrome/browser/android/preferences/pref_service_bridge.cc
diff --git a/chrome/browser/android/preferences/pref_service_bridge.cc b/chrome/browser/android/preferences/pref_service_bridge.cc
index 5b5f4b54ac3b2e812c18acfc28a2a45e8f9c3d3a..79366d0befb7deca54e7f7ccd74fe6fd31d40b8a 100644
--- a/chrome/browser/android/preferences/pref_service_bridge.cc
+++ b/chrome/browser/android/preferences/pref_service_bridge.cc
@@ -10,6 +10,7 @@
 #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"
@@ -36,6 +37,7 @@
 #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"
@@ -47,6 +49,7 @@ 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;
@@ -948,3 +951,40 @@ std::string PrefServiceBridge::GetAndroidPermissionForContentSetting(
 
   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;
+}