Fix sizing of non strech items

Summary:
Fixes the sizing of items so that under most scenarios it calcultes its height by it's content for non exact measurings. This introduces a new useLegacyStretchBehaviour flag on the config to opt out of this change as it is breaking.

See facebook/yoga#505
Closes https://github.com/facebook/yoga/pull/506

Reviewed By: astreet

Differential Revision: D4954016

Pulled By: emilsjolander

fbshipit-source-id: d28bd5d174cd76951fb94df85e3b0cfab7f81ff7

java/jni/YGJNI.cpp

@@ -408,6 +408,11 @@ void jni_YGConfigSetPointScaleFactor(alias_ref<jobject>, jlong nativePointer, jf
   YGConfigSetPointScaleFactor(config, pixelsInPoint);
 }
 
+void jni_YGConfigSetUseLegacyStretchBehaviour(alias_ref<jobject>, jlong nativePointer, jboolean useLegacyStretchBehaviour) {
+  const YGConfigRef config = _jlong2YGConfigRef(nativePointer);
+  YGConfigSetUseLegacyStretchBehaviour(config, useLegacyStretchBehaviour);
+}
+
 jint jni_YGNodeGetInstanceCount(alias_ref<jclass> clazz) {
   return YGNodeGetInstanceCount();
 }
@@ -504,6 +509,7 @@ jint JNI_OnLoad(JavaVM *vm, void *) {
                         YGMakeNativeMethod(jni_YGConfigSetExperimentalFeatureEnabled),
                         YGMakeNativeMethod(jni_YGConfigSetUseWebDefaults),
                         YGMakeNativeMethod(jni_YGConfigSetPointScaleFactor),
+                        YGMakeNativeMethod(jni_YGConfigSetUseLegacyStretchBehaviour),
                     });
   });
 }