make SetReceiveBufferSize and SetSendBufferSize return net error codes (instead of bools)

net/base/net_errors.cc

Index: net/base/net_errors.cc
diff --git a/net/base/net_errors.cc b/net/base/net_errors.cc
index a9d1443c913003615f2d4742deb06ecc6bf8d512..27f747bb6b339639eef8e7b243cd9bbb9d6a6112 100644
--- a/net/base/net_errors.cc
+++ b/net/base/net_errors.cc
@@ -59,4 +59,13 @@ Error FileErrorToNetError(base::File::Error file_error) {
   }
 }
 
+int MapSystemErrorWithDefault(int os_error, int default_net_error) {
+  int net_error = MapSystemError(os_error);
+  if (net_error != OK)
+    return net_error;
+  DLOG(WARNING)  << "OS Error was not set meaningfully " << os_error;

[wtc, 2014/04/09 15:34:49]

Hmm... the problem with this error message is that it doesn't have a context.
Here are some ideas to provide a context.

1. Also log default_net_error.

2. Add a "failed_function_name" argument to the function.

3. Dump a call stack.

Nit: "meaningfully" seems superfluous. "Error" doesn't need to be capitalized.

+  DCHECK_NE(default_net_error, OK);

[wtc, 2014/04/09 15:34:49]

This DCHECK should be at the beginning of the function, so that it is always
executed.

+  return default_net_error;
+}
+
 }  // namespace net