Update from https://crrev.com/303153

base/android/field_trial_list.cc

Index: base/android/field_trial_list.cc
diff --git a/base/android/field_trial_list.cc b/base/android/field_trial_list.cc
index 13f3cc5b18a0671cf775572f6c25d48cc9a21833..9cb38d2910624e7b4ce529d71503c7c935581ab2 100644
--- a/base/android/field_trial_list.cc
+++ b/base/android/field_trial_list.cc
@@ -22,6 +22,11 @@ static jstring FindFullName(JNIEnv* env,
       base::FieldTrialList::FindFullName(trial_name)).Release();
 }
 
+static jboolean TrialExists(JNIEnv* env, jclass clazz, jstring jtrial_name) {
+  std::string trial_name(ConvertJavaStringToUTF8(env, jtrial_name));
+  return base::FieldTrialList::TrialExists(trial_name);
+}
+
 namespace base {
 namespace android {