Move transport functions and variables to util (media/cast)

When building using jumbo, files get merged and functions and
variables with the same name may end up in the same namespace
and conflict. This happens in:
media/cast/net/cast_transport_impl.cc
media/cast/net/udp_transport_impl.cc

Since the functions and variables are identical they are
moved to a common util file.

Bug: 867350
Change-Id: I08747781d56b78e9a8783bfec870c7084183062a
Reviewed-on: https://chromium-review.googlesource.com/1152738
Commit-Queue: Chrome Cunningham (In Paris) <chcunningham@chromium.org>
Reviewed-by: Chrome Cunningham (In Paris) <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578596}

media/cast/BUILD.gn

@@ -102,6 +102,8 @@ source_set("net") {
     "net/rtp/rtp_parser.h",
     "net/rtp/rtp_sender.cc",
     "net/rtp/rtp_sender.h",
+    "net/transport_util.cc",
+    "net/transport_util.h",
     "net/udp_packet_pipe.cc",
     "net/udp_packet_pipe.h",
     "net/udp_transport_impl.cc",

media/cast/net/cast_transport_impl.cc

@@ -13,32 +13,22 @@
 #include "build/build_config.h"
 #include "media/cast/net/cast_transport_defines.h"
 #include "media/cast/net/rtcp/sender_rtcp_session.h"
+#include "media/cast/net/transport_util.h"
 #include "net/base/net_errors.h"
 
+using media::cast::transport_util::kOptionPacerMaxBurstSize;
+using media::cast::transport_util::kOptionPacerTargetBurstSize;
+using media::cast::transport_util::LookupOptionWithDefault;
+
 namespace media {
 namespace cast {
 
 namespace {
 
-// Options for PaceSender.
-const char kOptionPacerMaxBurstSize[] = "pacer_max_burst_size";
-const char kOptionPacerTargetBurstSize[] = "pacer_target_burst_size";
-
 // Wifi options.
 const char kOptionWifiDisableScan[] = "disable_wifi_scan";
 const char kOptionWifiMediaStreamingMode[] = "media_streaming_mode";
 
-int LookupOptionWithDefault(const base::DictionaryValue& options,
-                            const std::string& path,
-                            int default_value) {
-  int ret;
-  if (options.GetInteger(path, &ret)) {
-    return ret;
-  } else {
-    return default_value;
-  }
-}
-
 }  // namespace
 
 std::unique_ptr<CastTransport> CastTransport::Create(

media/cast/net/transport_util.cc

+// Copyright 2018 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 "media/cast/net/transport_util.h"
+
+namespace media {
+namespace cast {
+namespace transport_util {
+
+int LookupOptionWithDefault(const base::DictionaryValue& options,
+                            const std::string& path,
+                            int default_value) {
+  int ret;
+  if (options.GetInteger(path, &ret)) {
+    return ret;
+  } else {
+    return default_value;
+  }
+}
+
+}  // namespace transport_util
+}  // namespace cast
+}  // namespace media

media/cast/net/transport_util.h

+// Copyright 2018 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.
+
+#ifndef MEDIA_CAST_NET_TRANSPORT_UTIL_H_
+#define MEDIA_CAST_NET_TRANSPORT_UTIL_H_
+
+#include <string>
+
+#include "base/values.h"
+
+namespace media {
+namespace cast {
+namespace transport_util {
+
+// Options for PaceSender.
+const char kOptionPacerMaxBurstSize[] = "pacer_max_burst_size";
+const char kOptionPacerTargetBurstSize[] = "pacer_target_burst_size";
+
+int LookupOptionWithDefault(const base::DictionaryValue& options,
+                            const std::string& path,
+                            int default_value);
+
+}  // namespace transport_util
+}  // namespace cast
+}  // namespace media
+
+#endif  // MEDIA_CAST_NET_TRANSPORT_UTIL_H_

media/cast/net/udp_transport_impl.cc

@@ -11,12 +11,16 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "build/build_config.h"
+#include "media/cast/net/transport_util.h"
 #include "media/cast/net/udp_packet_pipe.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/log/net_log_source.h"
 #include "net/traffic_annotation/network_traffic_annotation.h"
 
+using media::cast::transport_util::kOptionPacerMaxBurstSize;
+using media::cast::transport_util::LookupOptionWithDefault;
+
 namespace media {
 namespace cast {
 
@@ -27,23 +31,11 @@ const char kOptionDscp[] = "DSCP";
 const char kOptionDisableNonBlockingIO[] = "disable_non_blocking_io";
 #endif
 const char kOptionSendBufferMinSize[] = "send_buffer_min_size";
-const char kOptionPacerMaxBurstSize[] = "pacer_max_burst_size";
 
 bool IsEmpty(const net::IPEndPoint& addr) {
   return (addr.address().empty() || addr.address().IsZero()) && !addr.port();
 }
 
-int LookupOptionWithDefault(const base::DictionaryValue& options,
-                            const std::string& path,
-                            int default_value) {
-  int ret;
-  if (options.GetInteger(path, &ret)) {
-    return ret;
-  } else {
-    return default_value;
-  }
-}
-
 int32_t GetTransportSendBufferSize(const base::DictionaryValue& options) {
   // Socket send buffer size needs to be at least greater than one burst
   // size.