Remove some uses of isdigit in net/, as it can be locale depedent.

net/quic/core/quic_spdy_stream.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/core/quic_spdy_stream.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
+#include "net/base/parse_number.h"
 #include "net/quic/core/quic_bug_tracker.h"
 #include "net/quic/core/quic_spdy_session.h"
 #include "net/quic/core/quic_utils.h"
 #include "net/quic/core/quic_write_blocked_list.h"
 #include "net/quic/core/spdy_utils.h"
 
 using base::IntToString;
 using base::StringPiece;
 using std::string;
 
@@ skipping 262 matching lines @@
 bool QuicSpdyStream::ParseHeaderStatusCode(const SpdyHeaderBlock& header,
                                            int* status_code) const {
   SpdyHeaderBlock::const_iterator it = header.find(":status");
   if (it == header.end()) {
     return false;
   }
   const StringPiece status(it->second);
   if (status.size() != 3) {
     return false;
   }
-  // First character must be an integer in range [1,5].
-  if (status[0] < '1' || status[0] > '5') {
+
+  unsigned int result;
+  if (!ParseUint32(status, &result, nullptr)) {
     return false;
   }
-  // The remaining two characters must be integers.
-  if (!isdigit(status[1]) || !isdigit(status[2])) {
+
+  // Valid status codes are only in the range [100, 599].
+  if (result < 100 || result >= 600) {
     return false;
   }
-  return StringToInt(status, status_code);
+
+  *status_code = static_cast<int>(result);
+  return true;
 }
 
 bool QuicSpdyStream::FinishedReadingTrailers() const {
   // If no further trailing headers are expected, and the decompressed trailers
   // (if any) have been consumed, then reading of trailers is finished.
   if (!fin_received()) {
     return false;
   } else if (!trailers_decompressed_) {
     return true;
   } else {
@@ skipping 16 matching lines @@
     QuicAckListenerInterface* ack_notifier_delegate) {
   if (spdy_session_->headers_stream() != nullptr &&
       spdy_session_->force_hol_blocking()) {
     return spdy_session_->headers_stream()->WritevStreamData(
         id(), iov, offset, fin, ack_notifier_delegate);
   }
   return QuicStream::WritevDataInner(iov, offset, fin, ack_notifier_delegate);
 }
 
 }  // namespace net