stream: Remove pipeOpts.chunkSize

It's not actually necessary for backwards compatibility, isn't
used anywhere, and isn't even tested.  Better to just remove it.

lib/_stream_readable.js

@@ -75,7 +75,6 @@ function ReadableState(options, stream) {
 
   // the number of writers that are awaiting a drain event in .pipe()s
   this.awaitDrain = 0;
-  this.pipeChunkSize = null;
 
   this.decoder = null;
   if (options.encoding) {
@@ -420,9 +419,6 @@ Readable.prototype.pipe = function(dest, pipeOpts) {
     cleanup();
   }
 
-  if (pipeOpts && pipeOpts.chunkSize)
-    state.pipeChunkSize = pipeOpts.chunkSize;
-
   function onend() {
     dest.end();
   }
@@ -520,8 +516,7 @@ function flow(src) {
     }
   }
 
-  while (state.pipesCount &&
-         null !== (chunk = src.read(state.pipeChunkSize))) {
+  while (state.pipesCount && null !== (chunk = src.read())) {
 
     if (state.pipesCount === 1)
       write(state.pipes, 0, null);

test/simple/test-stream2-fs.js

@@ -73,4 +73,4 @@ w.on('results', function(res) {
   console.log('ok');
 });
 
-r.pipe(w, { chunkSize: 10 });
+r.pipe(w);