DevTools socket tunnel.

components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/AbstractDataChannel.java

Index: components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/AbstractDataChannel.java
diff --git a/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/AbstractDataChannel.java b/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/AbstractDataChannel.java
new file mode 100644
index 0000000000000000000000000000000000000000..90687546d501615a0d41f39681bcabb645703b8b
--- /dev/null
+++ b/components/devtools_bridge/android/java/src/org/chromium/components/devtools_bridge/AbstractDataChannel.java
@@ -0,0 +1,49 @@
+// Copyright 2014 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.components.devtools_bridge;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Limited view on org.webrtc.DataChannel. Abstraction layer helps with:
+ * 1. Mocking in tests. There is no need to emulate full set of features of the DataChannel.
+ * 2. Allows both native and Java API implementation for WebRTC data channel.
+ * 3. Hides unused features.
+ * Only SCTP data channels supported.
+ */
+public abstract class AbstractDataChannel {

[mnaganov (inactive), 2014/09/12 13:37:29]

Do we need to mention here that data channel is threadsafe?

[SeRya, 2014/09/15 15:20:00]

It's worth to be mentioned indeed.

+    /**
+     *  Observer's callbacks are called on WebRTC signaling thread (or it's equivalent in tests).
+     */
+    public interface Observer {
+        // Only 2 states of channel are important here: OPEN and everything else.
+        void onStateChange(boolean open);

[mnaganov (inactive), 2014/09/12 13:37:29]

Does it make sense to use an enum here -- for clarity, and for potential
extension?

[SeRya, 2014/09/15 15:20:00]

Done.

+
+        // TEXT and BINARY messages should be handled equally. Size of the message is
+        // |message|.remaining(). |message| may reference to a native buffer on stack so
+        // the reference to the buffer must not outlive the invokation.

[mnaganov (inactive), 2014/09/12 13:37:29]

typo: invocation

[SeRya, 2014/09/15 15:20:00]

Done.

+        void onMessage(ByteBuffer message);
+    }
+
+    // Type is only significant for JavaScript-based counterpart. TEXT messages will
+    // be observed as strings, BINARY as ByteArray's.
+    public enum MessageType {
+        TEXT, BINARY
+    }
+
+    public abstract void registerObserver(Observer observer);
+
+    // Observer unregistration synchronized with signaling thread. If some data modified
+    // in observer callbacks without additional synchronization it's safe to access
+    // this data on the current thread after calling this method.
+    public abstract void unregisterObserver();
+
+    // Message size is |message|.remaining().
+    public abstract void send(ByteBuffer message, MessageType type);
+
+    public abstract void close();
+
+    public abstract void dispose();
+}