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..bbe975b3bacb5b153eef607166a301259c538f32 100644
--- a/chrome/browser/android/preferences/pref_service_bridge.cc
+++ b/chrome/browser/android/preferences/pref_service_bridge.cc
@@ -5,11 +5,14 @@
 #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"
@@ -36,6 +39,7 @@
 #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 +51,7 @@ 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;
@@ -111,6 +116,20 @@ 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
 
 // ----------------------------------------------------------------------------
@@ -948,3 +967,23 @@ std::string PrefServiceBridge::GetAndroidPermissionForContentSetting(
 
   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);
+}