Remove unused BidirectionalStream::SendData() method and implementations.

components/cronet/android/cronet_bidirectional_stream_adapter.cc

Index: components/cronet/android/cronet_bidirectional_stream_adapter.cc
diff --git a/components/cronet/android/cronet_bidirectional_stream_adapter.cc b/components/cronet/android/cronet_bidirectional_stream_adapter.cc
index a637d4903b3453e5e81c843322559a32d8d918ab..104cb437b4a28bcfeb56601878be1fd02a9e7578 100644
--- a/components/cronet/android/cronet_bidirectional_stream_adapter.cc
+++ b/components/cronet/android/cronet_bidirectional_stream_adapter.cc
@@ -398,15 +398,9 @@ void CronetBidirectionalStreamAdapter::WritevDataOnNetworkThread(
 
   pending_write_data_ = std::move(pending_write_data);
   bool end_of_stream = pending_write_data_->jwrite_end_of_stream == JNI_TRUE;
-  if (pending_write_data_->write_buffer_list.size() == 1) {
-    bidi_stream_->SendData(pending_write_data_->write_buffer_list[0],
-                           pending_write_data_->write_buffer_len_list[0],
-                           end_of_stream);
-  } else {
-    bidi_stream_->SendvData(pending_write_data_->write_buffer_list,
-                            pending_write_data_->write_buffer_len_list,
-                            end_of_stream);
-  }
+  bidi_stream_->SendvData(pending_write_data_->write_buffer_list,
+                          pending_write_data_->write_buffer_len_list,
+                          end_of_stream);
 }
 
 void CronetBidirectionalStreamAdapter::DestroyOnNetworkThread(