The JNI generator will generate JNI binding file under "(SHARED_INTERMEDIATE_DIR)/<(jni_gen_package)/jni/" during the build time.
For example, the corresponding JNI binding file for ContentViewCore.java is "out/Debug/gen/content/jni/ContentViewCore_jni.h". And you can see the native method of 'nativeEvaluateJavaScript':
static void EvaluateJavaScript(JNIEnv* env, jobject jcaller,...