Allowing a Java object field to be null in a new JNI helper method.

webrtc/api/java/jni/jni_helpers.h

Index: webrtc/api/java/jni/jni_helpers.h
diff --git a/webrtc/api/java/jni/jni_helpers.h b/webrtc/api/java/jni/jni_helpers.h
index 98dcc38b5348b4ad8157cb6752711ed0e438388a..2832df14b3be71cb0ec7cd6d363a4ce6d417bd4f 100644
--- a/webrtc/api/java/jni/jni_helpers.h
+++ b/webrtc/api/java/jni/jni_helpers.h
@@ -64,8 +64,11 @@ jfieldID GetFieldID(JNIEnv* jni, jclass c, const char* name,
 
 jclass GetObjectClass(JNIEnv* jni, jobject object);
 
+// Throws an exception if the object field is null.

[pthatcher1, 2016/04/11 19:39:29]

Doesn't the code actually crash?  

[Taylor Brandstetter, 2016/04/11 23:13:38]

Oh yeah. It calls abort(). I'll make a CL to fix this comment.

 jobject GetObjectField(JNIEnv* jni, jobject object, jfieldID id);

[pthatcher1, 2016/04/11 19:39:29]

Can we rename this one GetNonNullObjectField to make it clear things may throw
an exception (or crash)?

[Taylor Brandstetter, 2016/04/11 23:13:38]

Since you, Vlad and I prefer that naming, it seems worth doing. I'll do it in
the new CL.

 
+jobject GetNullableObjectField(JNIEnv* jni, jobject object, jfieldID id);
+
 jstring GetStringField(JNIEnv* jni, jobject object, jfieldID id);
 
 jlong GetLongField(JNIEnv* jni, jobject object, jfieldID id);