Implement standard interface for toggling experimental features

Summary: We want to start experimenting with changes to the library in a more controlled and easier to measure manner. This diff adds the basics of an experiment layer to csslayout.

Reviewed By: gkassabli

Differential Revision: D4174260

fbshipit-source-id: ad3667183810c02833fba9a1276f89286e848fcd

java/com/facebook/csslayout/CSSExperimentalFeature.java

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package com.facebook.csslayout;
+
+public enum CSSExperimentalFeature {
+}

java/com/facebook/csslayout/CSSNode.java

@@ -40,6 +40,20 @@ public class CSSNode implements CSSNodeAPI<CSSNode> {
     jni_CSSLayoutSetLogger(logger);
   }
 
+  private static native void jni_CSSLayoutSetExperimentalFeatureEnabled(
+      int feature,
+      boolean enabled);
+  public static void setExperimentalFeatureEnabled(
+      CSSExperimentalFeature feature,
+      boolean enabled) {
+    jni_CSSLayoutSetExperimentalFeatureEnabled(feature.ordinal(), enabled);
+  }
+
+  private static native boolean jni_CSSLayoutIsExperimentalFeatureEnabled(int feature);
+  public static boolean isExperimentalFeatureEnabled(CSSExperimentalFeature feature) {
+    return jni_CSSLayoutIsExperimentalFeatureEnabled(feature.ordinal());
+  }
+
   private CSSNode mParent;
   private List<CSSNode> mChildren;
   private MeasureFunction mMeasureFunction;