Make URLRequest::Read to return net errors or bytes read instead of a bool

net/url_request/url_request_job.cc

Index: net/url_request/url_request_job.cc
diff --git a/net/url_request/url_request_job.cc b/net/url_request/url_request_job.cc
index 08f0ab4c6175c9925d0535e4b5f79fe764206f6f..b871c4c0bb3ebccc635bbd2c14adfe6b9479456f 100644
--- a/net/url_request/url_request_job.cc
+++ b/net/url_request/url_request_job.cc
@@ -160,43 +160,42 @@ void URLRequestJob::Kill() {
 // This function calls ReadRawData to get stream data. If a filter exists, it
 // passes the data to the attached filter. It then returns the output from
 // filter back to the caller.
-bool URLRequestJob::Read(IOBuffer* buf, int buf_size, int *bytes_read) {
+int URLRequestJob::Read(IOBuffer* buf, int buf_size) {
   DCHECK_LT(buf_size, 1000000);  // Sanity check.
   DCHECK(buf);
-  DCHECK(bytes_read);
   DCHECK(!filtered_read_buffer_);
   DCHECK_EQ(0, filtered_read_buffer_len_);
 
   Error error = OK;
-  *bytes_read = 0;
+  int bytes_read = 0;
 
   // Skip Filter if not present.
   if (!filter_) {
-    error = ReadRawDataHelper(buf, buf_size, bytes_read);
+    error = ReadRawDataHelper(buf, buf_size, &bytes_read);
   } else {
     // Save the caller's buffers while we do IO
     // in the filter's buffers.
     filtered_read_buffer_ = buf;
     filtered_read_buffer_len_ = buf_size;
 
-    error = ReadFilteredData(bytes_read);
+    error = ReadFilteredData(&bytes_read);
 
     // Synchronous EOF from the filter.
-    if (error == OK && *bytes_read == 0)
+    if (error == OK && bytes_read == 0)
       DoneReading();
   }
 
   if (error == OK) {
     // If URLRequestJob read zero bytes, the job is at EOF.
-    if (*bytes_read == 0)
+    if (bytes_read == 0)
       NotifyDone(URLRequestStatus());
   } else if (error == ERR_IO_PENDING) {
-    *bytes_read = ERR_IO_PENDING;
+    bytes_read = ERR_IO_PENDING;
   } else {
     NotifyDone(URLRequestStatus::FromError(error));
-    *bytes_read = error;
+    bytes_read = error;
   }
-  return error == OK;
+  return bytes_read;

[mmenke, 2016/08/30 22:09:12]

Suggest re-ordering these and using early returns.  Think separate cases are
easier to follow, and now don't need separate logic to set bytes_read and handle
the return value.

Something like:

if (error == ERR_IO_PENDING)
  return ERR_IO_PENDING;

if (error < 0) {
  ...
  return error;
}

if (bytes_read == 0)
  // Early return not needed here.

[maksims (do not use this acc), 2016/08/31 11:16:59]

Done.

 }
 
 void URLRequestJob::StopCaching() {