[Web MIDI] Use Android MIDI API.

media/midi/java/src/org/chromium/media/midi/MidiInputPortAndroid.java

Index: media/midi/java/src/org/chromium/media/midi/MidiInputPortAndroid.java
diff --git a/media/midi/java/src/org/chromium/media/midi/MidiInputPortAndroid.java b/media/midi/java/src/org/chromium/media/midi/MidiInputPortAndroid.java
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index 0000000000000000000000000000000000000000..aab30e49cb10e755be2a8f8bb459fa88f47b3fa9
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+++ b/media/midi/java/src/org/chromium/media/midi/MidiInputPortAndroid.java
@@ -0,0 +1,94 @@
+// 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.
+
+package org.chromium.media.midi;
+
+import android.media.midi.MidiDevice;
+import android.media.midi.MidiOutputPort;
+import android.media.midi.MidiReceiver;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+
+import java.io.IOException;
+
+// Note "InputPort" is named in the Web MIDI manner. It corresponds to MidiOutputPort class in the
+// Android API.
+/**
+ * A MidiInputPortAndroid provides data to the associated media::midi::MidiInputPortAndroid object.
+ */
+@JNINamespace("media::midi")
+class MidiInputPortAndroid {
+    /**
+     * The underlying port.
+     */
+    private MidiOutputPort mPort;
+    /**
+     * A pointer to a media::midi::MidiInputPortAndroid object.
+     */
+    private long mNativeReceiverPointer;
+    /**
+     * The device this port belongs to.
+     */
+    private final MidiDevice mDevice;
+    /**
+     * The index of the port in the associated device.
+     */
+    private final int mIndex;
+
+    /**
+     * constructor
+     * @param device the device this port belongs to.
+     * @param index the index of the port in the associated device.
+     */
+    MidiInputPortAndroid(MidiDevice device, int index) {
+        mDevice = device;
+        mIndex = index;
+    }
+
+    /**
+     * Registers this object to the underlying port so as to the C++ function will be called with
+     * the given C++ object when data arrives.
+     * @param nativeReceiverPointer a pointer to a media::midi::MidiInputPortAndroid object.
+     * @return true if this operation succeeds or the port is already open.
+     */
+    @CalledByNative
+    boolean open(long nativeReceiverPointer) {
+        if (mPort != null) {
+            return true;
+        }
+        mPort = mDevice.openOutputPort(mIndex);
+        if (mPort == null) {
+            return false;
+        }
+        mNativeReceiverPointer = nativeReceiverPointer;
+        mPort.connect(new MidiReceiver() {
+            @Override
+            public void onSend(byte[] bs, int offset, int count, long timestamp) {
+                nativeOnData(mNativeReceiverPointer, bs, offset, count, timestamp);
+            }
+        });
+        return true;
+    }
+
+    /**
+     * Closes the port.
+     */
+    @CalledByNative
+    void close() {
+        if (mPort == null) {
+            return;
+        }
+        try {
+            mPort.close();
+        } catch (IOException e) {
+            // We can do nothing here. Just ignore the error.
+        }
+        mNativeReceiverPointer = 0;
+        mPort = null;
+    }
+
+    private static native void nativeOnData(
+            long nativeMidiInputPortAndroid, byte[] bs, int offset, int count, long timestamp);
+}