Web MIDI: fix multi-threading problem around message buffer handling

content/browser/renderer_host/media/midi_host.cc

Index: content/browser/renderer_host/media/midi_host.cc
diff --git a/content/browser/renderer_host/media/midi_host.cc b/content/browser/renderer_host/media/midi_host.cc
index b0b0e7692f270b4454cb8e26482179dc9b64c040..080eb3e8e1dee69436b811a2843ec2648f58c76f 100644
--- a/content/browser/renderer_host/media/midi_host.cc
+++ b/content/browser/renderer_host/media/midi_host.cc
@@ -88,7 +88,7 @@ void MIDIHost::OnStartSession(int client_id) {
        output_ports));
 }
 
-void MIDIHost::OnSendData(int port,
+void MIDIHost::OnSendData(uint32 port,
                           const std::vector<uint8>& data,
                           double timestamp) {
   if (!midi_manager_)
@@ -111,13 +111,12 @@ void MIDIHost::OnSendData(int port,
   // this client access.  We'll likely need to pass a GURL
   // here to compare against our permissions.
   if (data[0] >= kSysExMessage)
-      return;
+    return;
 
   midi_manager_->DispatchSendMIDIData(
       this,
-      port,
-      &data[0],
-      data.size(),
+      static_cast<size_t>(port),

[palmer, 2013/08/26 17:43:25]

You don't need to do this if you define |SendMIDIData| and
|SendMIDIDataOnIOThread| in midi_message_filter.{h,cc} to take a uint32_t.

[Takashi Toyoshima, 2013/08/27 07:14:33]

Done.

+      data,
       timestamp);
 
   sent_bytes_in_flight_ += data.size();