Added the JNI interface to get and set RtpParameters and the maximum bitrate limits.

webrtc/api/java/jni/jni_helpers.cc

Index: webrtc/api/java/jni/jni_helpers.cc
diff --git a/webrtc/api/java/jni/jni_helpers.cc b/webrtc/api/java/jni/jni_helpers.cc
index 32092e65f8b7e8a2c94cb69b393ccc5f4f2ebb2e..41d34247f2baae1c96a7f5c4022bd90e6eacab07 100644
--- a/webrtc/api/java/jni/jni_helpers.cc
+++ b/webrtc/api/java/jni/jni_helpers.cc
@@ -272,4 +272,55 @@ ScopedLocalRefFrame::~ScopedLocalRefFrame() {
   jni_->PopLocalFrame(NULL);
 }
 
+// Creates an iterator representing the end of any collection.
+Iterator::Iterator() : iterator_(NULL) {}
+
+// Creates an iterator pointing to the beginning of the specified collection.
+Iterator::Iterator(JNIEnv* jni, jobject iterable) : jni_(jni) {
+  jclass j_class = GetObjectClass(jni, iterable);
+  jmethodID iterator_id =
+      GetMethodID(jni, j_class, "iterator", "()Ljava/util/Iterator;");
+  iterator_ = jni->CallObjectMethod(iterable, iterator_id);
+  CHECK_EXCEPTION(jni) << "error during CallObjectMethod";
+
+  if (iterator_ == NULL) {
+    // TODO(skvlad): Should this be an exception instead?

[Taylor Brandstetter, 2016/03/22 01:16:36]

That seems reasonable. Just use "RTC_CHECK(iterator_ != NULL)"

[skvlad, 2016/03/22 02:19:59]

Done.

+    return;
+  }
+
+  jclass iterator_class = GetObjectClass(jni, iterator_);
+  has_next_id_ = GetMethodID(jni, iterator_class, "hasNext", "()Z");
+  next_id_ = GetMethodID(jni, iterator_class, "next", "()Ljava/lang/Object;");
+
+  // Start at the first element in the collection
+  ++(*this);
+}
+
+// Move constructor - necessary to be able to return iterator types from
+// functions
+Iterator::Iterator(Iterator&& other)
+    : jni_(std::move(other.jni_)),
+      iterator_(std::move(other.iterator_)),
+      value_(std::move(other.value_)),
+      has_next_id_(std::move(other.has_next_id_)),
+      next_id_(std::move(other.next_id_)){};
+
+// Advances the iterator one step
+Iterator& Iterator::operator++() {
+  if (iterator_ == NULL) {
+    // Can't iterate past the end
+    return *this;
+  }
+  bool has_next = jni_->CallBooleanMethod(iterator_, has_next_id_);
+  CHECK_EXCEPTION(jni_) << "error during CallBooleanMethod";
+  if (!has_next) {
+    iterator_ = NULL;
+    return *this;
+  }
+
+  value_ = jni_->CallObjectMethod(iterator_, next_id_);
+  CHECK_EXCEPTION(jni_) << "error during CallObjectMethod";
+  return *this;
+}
+
 }  // namespace webrtc_jni