Use thread with looper and native message loop for vsync service.

shell/android/apk/src/org/chromium/mojo/shell/NativeHandlerThread.java

Index: shell/android/apk/src/org/chromium/mojo/shell/NativeHandlerThread.java
diff --git a/shell/android/apk/src/org/chromium/mojo/shell/NativeHandlerThread.java b/shell/android/apk/src/org/chromium/mojo/shell/NativeHandlerThread.java
new file mode 100644
index 0000000000000000000000000000000000000000..334372ebd9995acea71635798269d6fc81c3aef8
--- /dev/null
+++ b/shell/android/apk/src/org/chromium/mojo/shell/NativeHandlerThread.java
@@ -0,0 +1,54 @@
+// 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.mojo.shell;
+
+import android.os.HandlerThread;
+
+import org.chromium.base.JNINamespace;
+
+/**
+ * Handler thread associated with a native message loop.
+ */
+@JNINamespace("shell")
+public class NativeHandlerThread extends HandlerThread {
+    // The native message loop.
+    private long mNativeMessageLoop = 0;
+
+    /**
+     * Constructor.
+     */
+    public NativeHandlerThread(String name) {
+        super(name);
+    }
+
+    /**
+     * @see HandlerThread#run()
+     */
+    @Override
+    public void run() {
+        try {
+            super.run();
+        } finally {
+            if (mNativeMessageLoop != 0) {
+                nativeDeleteMessageLoop(mNativeMessageLoop);
+            }
+        }
+    }
+
+    /**
+     * @see HandlerThread#onLooperPrepared()
+     */
+    @Override
+    protected void onLooperPrepared() {
+        if (mNativeMessageLoop == 0) {
+            mNativeMessageLoop = nativeCreateMessageLoop();
+        }
+        super.onLooperPrepared();
+    }
+
+    native long nativeCreateMessageLoop();
+
+    native void nativeDeleteMessageLoop(long messageLoop);
+}