[Field trial params] Getting field trial params by feature name in Java.

chrome/browser/android/chrome_feature_list.cc

Index: chrome/browser/android/chrome_feature_list.cc
diff --git a/chrome/browser/android/chrome_feature_list.cc b/chrome/browser/android/chrome_feature_list.cc
index 557aa7e883922f72b3f8a7774139c14f7bbcbfe4..efee6c6a1f32070b8ca3ed7be0794be72004a748 100644
--- a/chrome/browser/android/chrome_feature_list.cc
+++ b/chrome/browser/android/chrome_feature_list.cc
@@ -21,7 +21,9 @@
 #include "jni/ChromeFeatureList_jni.h"
 
 using base::android::ConvertJavaStringToUTF8;
+using base::android::ConvertUTF8ToJavaString;
 using base::android::JavaParamRef;
+using base::android::ScopedJavaLocalRef;
 
 namespace chrome {
 namespace android {
@@ -74,6 +76,16 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &password_manager::features::kViewPasswords,
 };
 
+const base::Feature* FindFeatureExposedToJava(const std::string& feature_name) {
+  for (size_t i = 0; i < arraysize(kFeaturesExposedToJava); ++i) {
+    if (kFeaturesExposedToJava[i]->name == feature_name)
+      return kFeaturesExposedToJava[i];
+  }
+  NOTREACHED() << "Features queried via ChromeFeatureList must be present in "
+                  "|kFeaturesExposedToJava|.";
+  return nullptr;
+}
+
 }  // namespace
 
 // Alphabetical:
@@ -159,14 +171,22 @@ const base::Feature kWebVRCardboardSupport{
 static jboolean IsEnabled(JNIEnv* env,
                           const JavaParamRef<jclass>& clazz,
                           const JavaParamRef<jstring>& jfeature_name) {
-  const std::string feature_name = ConvertJavaStringToUTF8(env, jfeature_name);
-  for (size_t i = 0; i < arraysize(kFeaturesExposedToJava); ++i) {
-    if (kFeaturesExposedToJava[i]->name == feature_name)
-      return base::FeatureList::IsEnabled(*kFeaturesExposedToJava[i]);
-  }
-  // Features queried via this API must be present in |kFeaturesExposedToJava|.
-  NOTREACHED();
-  return false;
+  const base::Feature* feature =
+      FindFeatureExposedToJava(ConvertJavaStringToUTF8(env, jfeature_name));
+  return base::FeatureList::IsEnabled(*feature);
+}
+
+static ScopedJavaLocalRef<jstring> GetFieldTrialParamByFeature(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& clazz,
+    const JavaParamRef<jstring>& jfeature_name,
+    const JavaParamRef<jstring>& jparam_name) {
+  const base::Feature* feature =
+      FindFeatureExposedToJava(ConvertJavaStringToUTF8(env, jfeature_name));
+  const std::string& param_name = ConvertJavaStringToUTF8(env, jparam_name);
+  const std::string& param_value =
+      base::GetFieldTrialParamValueByFeature(*feature, param_name);
+  return ConvertUTF8ToJavaString(env, param_value);
 }
 
 static jint GetFieldTrialParamByFeatureAsInt(
@@ -175,18 +195,37 @@ static jint GetFieldTrialParamByFeatureAsInt(
     const JavaParamRef<jstring>& jfeature_name,
     const JavaParamRef<jstring>& jparam_name,
     const jint jdefault_value) {
-  const std::string feature_name = ConvertJavaStringToUTF8(env, jfeature_name);
-  const std::string param_name = ConvertJavaStringToUTF8(env, jparam_name);
-  int default_value = static_cast<int>(jdefault_value);
+  const base::Feature* feature =
+      FindFeatureExposedToJava(ConvertJavaStringToUTF8(env, jfeature_name));
+  const std::string& param_name = ConvertJavaStringToUTF8(env, jparam_name);
+  return base::GetFieldTrialParamByFeatureAsInt(*feature, param_name,
+                                                jdefault_value);
+}
 
-  for (size_t i = 0; i < arraysize(kFeaturesExposedToJava); ++i) {
-    if (kFeaturesExposedToJava[i]->name == feature_name)
-      return base::GetFieldTrialParamByFeatureAsInt(
-          *kFeaturesExposedToJava[i], param_name, default_value);
-  }
-  // Features queried via this API must be present in |kFeaturesExposedToJava|.
-  NOTREACHED();
-  return jdefault_value;
+static jdouble GetFieldTrialParamByFeatureAsDouble(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& clazz,
+    const JavaParamRef<jstring>& jfeature_name,
+    const JavaParamRef<jstring>& jparam_name,
+    const jdouble jdefault_value) {
+  const base::Feature* feature =
+      FindFeatureExposedToJava(ConvertJavaStringToUTF8(env, jfeature_name));
+  const std::string& param_name = ConvertJavaStringToUTF8(env, jparam_name);
+  return base::GetFieldTrialParamByFeatureAsDouble(*feature, param_name,
+                                                   jdefault_value);
+}
+
+static jboolean GetFieldTrialParamByFeatureAsBoolean(
+    JNIEnv* env,
+    const JavaParamRef<jclass>& clazz,
+    const JavaParamRef<jstring>& jfeature_name,
+    const JavaParamRef<jstring>& jparam_name,
+    const jboolean jdefault_value) {
+  const base::Feature* feature =
+      FindFeatureExposedToJava(ConvertJavaStringToUTF8(env, jfeature_name));
+  const std::string& param_name = ConvertJavaStringToUTF8(env, jparam_name);
+  return base::GetFieldTrialParamByFeatureAsBool(*feature, param_name,
+                                                 jdefault_value);
 }
 
 bool RegisterChromeFeatureListJni(JNIEnv* env) {