libaddressinput - one less copy when downloading data

net/url_request/test_url_fetcher_factory.cc

Index: net/url_request/test_url_fetcher_factory.cc
diff --git a/net/url_request/test_url_fetcher_factory.cc b/net/url_request/test_url_fetcher_factory.cc
index 0a96153d6e6dc3516747a717be7c6523bce2d03f..2a88c42e2aba0aa9f0848f7f1c88cfe43803d7fc 100644
--- a/net/url_request/test_url_fetcher_factory.cc
+++ b/net/url_request/test_url_fetcher_factory.cc
@@ -11,6 +11,7 @@
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "net/base/host_port_pair.h"
+#include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_fetcher_delegate.h"
@@ -155,6 +156,16 @@ void TestURLFetcher::SaveResponseToTemporaryFile(
 
 void TestURLFetcher::SaveResponseWithWriter(
     scoped_ptr<URLFetcherResponseWriter> response_writer) {
+  if (fake_response_destination_ == STRING) {
+    response_writer_ = response_writer.Pass();
+    response_writer_->Initialize(CompletionCallback());
+
+    scoped_refptr<IOBuffer> buffer = new StringIOBuffer(fake_response_string_);

[Ryan Sleevi, 2014/01/31 21:03:17]

pedantic nit: buffer(new StringIOBuffer(...)) ?

[Evan Stade, 2014/01/31 22:56:47]

Done.

+    response_writer_->Write(buffer.get(),
+                            fake_response_string_.size(),
+                            CompletionCallback());

[Ryan Sleevi, 2014/01/31 21:03:17]

This doesn't fully match the URLFetcher / URLFetcherResponseWriter interface.

If you're going to allow callers to supply an arbitrary URLFRW, I feel like we
should at least try to not violate 'least surprise' here.

Namely,
https://code.google.com/p/chromium/codesearch#chromium/src/net/url_request/ur...

Write() may not write all of the data from fake_response_string_, so we should
try to continue writing more.

[Evan Stade, 2014/01/31 22:24:57]

well, it has several flaws:

a) SetResponseString must have been previously called (as opposed to being
called afterwards)
b) async Writers are not supported
c) writers that don't write all of buffer will fail (as you've noted)

Fixing all these things would require a bit of effort. Spending effort on code
to support tests which don't exist seems like a bit of a waste, I think. No one
bothered to implement SaveResponseWithWriter at all (until it was needed), now
it's partially implemented, which seems like an improvement.

[Evan Stade, 2014/01/31 22:56:47]

Done.

+    response_writer_->Finish(CompletionCallback());
+  }
 }
 
 HttpResponseHeaders* TestURLFetcher::GetResponseHeaders() const {