[WebMIDI] MIDIManager::create should return non-null object.

media/midi/midi_manager.cc

Index: media/midi/midi_manager.cc
diff --git a/media/midi/midi_manager.cc b/media/midi/midi_manager.cc
index 6d3f1d30b959139aaad7df5237090fc550b7f462..baea8b17a745c014078f77084c853312720adec3 100644
--- a/media/midi/midi_manager.cc
+++ b/media/midi/midi_manager.cc
@@ -12,7 +12,7 @@ namespace media {
 #if !defined(OS_MACOSX) && !defined(OS_WIN)
 // TODO(crogers): implement MIDIManager for other platforms.
 MIDIManager* MIDIManager::Create() {
-  return NULL;
+  return new MIDIManager;
 }
 #endif
 
@@ -43,6 +43,17 @@ void MIDIManager::EndSession(MIDIManagerClient* client) {
     clients_.erase(i);
 }
 
+void MIDIManager::DispatchSendMIDIData(MIDIManagerClient* client,
+                                       uint32 port_index,
+                                       const std::vector<uint8>& data,
+                                       double timestamp) {
+  NOTREACHED();
+}
+
+bool MIDIManager::Initialize() {
+  return false;
+}
+
 void MIDIManager::AddInputPort(const MIDIPortInfo& info) {
   input_ports_.push_back(info);
 }