Implement Drain() on HttpPipelinedStream.

net/http/http_response_body_drainer.cc

Index: net/http/http_response_body_drainer.cc
diff --git a/net/http/http_response_body_drainer.cc b/net/http/http_response_body_drainer.cc
index aefb18026528f2b90307349fc153e15cbdd7d3c6..718b5ae7ac38eead6c4bf8091cc0b25602c0d9cb 100644
--- a/net/http/http_response_body_drainer.cc
+++ b/net/http/http_response_body_drainer.cc
@@ -25,7 +25,14 @@ HttpResponseBodyDrainer::HttpResponseBodyDrainer(HttpStream* stream)
 HttpResponseBodyDrainer::~HttpResponseBodyDrainer() {}
 
 void HttpResponseBodyDrainer::Start(HttpNetworkSession* session) {
-  read_buf_ = new IOBuffer(kDrainBodyBufferSize);
+  StartWithSize(session, kDrainBodyBufferSize);
+}
+
+void HttpResponseBodyDrainer::StartWithSize(HttpNetworkSession* session,
+                                            int num_bytes_to_drain) {
+  DCHECK_LT(0, num_bytes_to_drain);
+  read_size_ = num_bytes_to_drain;
+  read_buf_ = new IOBuffer(read_size_);

[mmenke, 2011/11/18 15:45:38]

This could be a very large amount of memory, for, say, a download.  I'd suggest
just failing if num_bytes_to_drain > kDrainBodyBufferSize.  And we need a unit
test for that case, of course.

[James Simonsen, 2011/11/22 01:24:20]

Done.

   next_state_ = STATE_DRAIN_RESPONSE_BODY;
   int rv = DoLoop(OK);
 
@@ -71,7 +78,7 @@ int HttpResponseBodyDrainer::DoDrainResponseBody() {
   next_state_ = STATE_DRAIN_RESPONSE_BODY_COMPLETE;
 
   return stream_->ReadResponseBody(
-      read_buf_, kDrainBodyBufferSize - total_read_,
+      read_buf_, read_size_ - total_read_,
       &io_callback_);
 }