[Web MIDI] Use Android MIDI API.

media/midi/midi_input_port_android.cc

Index: media/midi/midi_input_port_android.cc
diff --git a/media/midi/midi_input_port_android.cc b/media/midi/midi_input_port_android.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1f1a9557c84f0ed6e436d9135e36d64cd27d3e74
--- /dev/null
+++ b/media/midi/midi_input_port_android.cc
@@ -0,0 +1,41 @@
+// Copyright 2015 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/midi/midi_input_port_android.h"
+
+#include "base/android/jni_array.h"
+#include "jni/MidiInputPortAndroid_jni.h"
+
+namespace media {
+namespace midi {
+
+MidiInputPortAndroid::MidiInputPortAndroid(JNIEnv* env,
+                                           jobject raw,
+                                           Delegate* delegate)
+    : delegate_(delegate) {
+  Java_MidiInputPortAndroid_connect(env, raw, reinterpret_cast<jlong>(this));
+}
+
+MidiInputPortAndroid::~MidiInputPortAndroid() {}
+
+void MidiInputPortAndroid::OnData(JNIEnv* env,
+                                  jobject caller,
+                                  jbyteArray data,
+                                  jint offset,
+                                  jint size,
+                                  jlong timestamp) {
+  std::vector<uint8> bytes;
+  base::android::JavaByteArrayToByteVector(env, data, &bytes);
+
+  // We don't use |timestamp| because MidiManager wants base::TimeTicks.

[philburk, 2015/08/19 01:40:15]

Ignoring timestamp can cause rendering errors. Some messages may get rendered
out of order.
Can you convert the timestamp, which is MONOTONIC nanoseconds, into
base::TimeTicks?

[yhirano, 2015/08/19 06:32:03]

Done.

+  const uint8* head = bytes.size() ? &bytes[offset] : nullptr;
+  delegate_->OnReceivedData(this, head, size, base::TimeTicks::Now());
+}
+
+bool MidiInputPortAndroid::Register(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace midi
+}  // namespace media