Cast: Let the extension control if DSCP is on or off.

chrome/renderer/extensions/cast_streaming_native_handler.cc

Index: chrome/renderer/extensions/cast_streaming_native_handler.cc
diff --git a/chrome/renderer/extensions/cast_streaming_native_handler.cc b/chrome/renderer/extensions/cast_streaming_native_handler.cc
index 9b50ae1db578a73b63ff6c0d5c2392ba93c4966c..8fae11904b969df9281123bc378e808dd6c46729 100644
--- a/chrome/renderer/extensions/cast_streaming_native_handler.cc
+++ b/chrome/renderer/extensions/cast_streaming_native_handler.cc
@@ -184,6 +184,9 @@ CastStreamingNativeHandler::CastStreamingNativeHandler(ScriptContext* context)
   RouteFunction("SetDestinationCastUdpTransport",
       base::Bind(&CastStreamingNativeHandler::SetDestinationCastUdpTransport,
                  base::Unretained(this)));
+  RouteFunction("SetOptionsCastUdpTransport",
+      base::Bind(&CastStreamingNativeHandler::SetOptionsCastUdpTransport,
+                 base::Unretained(this)));
   RouteFunction("ToggleLogging",
                 base::Bind(&CastStreamingNativeHandler::ToggleLogging,
                            base::Unretained(this)));
@@ -458,6 +461,28 @@ void CastStreamingNativeHandler::SetDestinationCastUdpTransport(
   transport->SetDestination(net::IPEndPoint(ip, destination->port));
 }
 
+void CastStreamingNativeHandler::SetOptionsCastUdpTransport(
+    const v8::FunctionCallbackInfo<v8::Value>& args) {
+  CHECK_EQ(2, args.Length());
+  CHECK(args[0]->IsInt32());
+  CHECK(args[1]->IsString());
+
+  const int transport_id = args[0]->ToInt32()->Value();
+  CastUdpTransport* transport = GetUdpTransportOrThrow(transport_id);
+  if (!transport)
+    return;
+
+  scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
+  std::string option_data;

[Alpha Left Google, 2014/09/09 00:30:45]

If the option is using the type base::DictionaryValue you can use |converter| to
convert it into base::DictionaryValue easily. Note that IPC system supports
base::DictionaryValue already.

[hubbe, 2014/09/09 20:10:01]

Done.

+  if (args[1]->IsNull()) {
+    args.GetIsolate()->ThrowException(v8::Exception::TypeError(
+        v8::String::NewFromUtf8(args.GetIsolate(), kUnableToConvertArgs)));
+  } else {
+    option_data = *v8::String::Utf8Value(args[1]);
+  }
+  transport->SetOptions(option_data);
+}
+
 void CastStreamingNativeHandler::ToggleLogging(
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(2, args.Length());