[android_webview] Add a generic callback JNI bridge.

android_webview/unittestjava/src/org/chromium/android_webview/unittest/CallbackJNIBridgeUnittest.java

Index: android_webview/unittestjava/src/org/chromium/android_webview/unittest/CallbackJNIBridgeUnittest.java
diff --git a/android_webview/unittestjava/src/org/chromium/android_webview/unittest/CallbackJNIBridgeUnittest.java b/android_webview/unittestjava/src/org/chromium/android_webview/unittest/CallbackJNIBridgeUnittest.java
new file mode 100644
index 0000000000000000000000000000000000000000..a09b7301641bf7875287556cffa6ff43ce3749c0
--- /dev/null
+++ b/android_webview/unittestjava/src/org/chromium/android_webview/unittest/CallbackJNIBridgeUnittest.java
@@ -0,0 +1,50 @@
+// Copyright 2013 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.android_webview.unittest;
+
+import android.webkit.ValueCallback;
+
+import org.chromium.base.CalledByNative;
+
+class CallbackJNIBridgeUnittest {
+  private CallbackJNIBridgeUnittest() {
+  }
+
+  private static class ValueCallbackInt implements ValueCallback<Integer> {
+      private boolean mHasValue;
+      private int mValue;
+
+      public boolean getHasValue() {
+          return mHasValue;
+      }
+
+      public int getValue() {
+          return mValue;
+      }
+
+      @Override
+      public void onReceiveValue(Integer value) {
+          assert !mHasValue;
+          mHasValue = true;
+          mValue = value;
+      }
+  }
+
+  @CalledByNative
+  static ValueCallbackInt createValueCallbackInt() {
+      return new ValueCallbackInt();
+  }
+
+  @CalledByNative
+  static boolean checkValueCallbackIntValue(ValueCallbackInt callback, int expectedValue) {
+      return callback.getHasValue() && callback.getValue() == expectedValue;
+  }
+
+  @SuppressWarnings("unchecked")
+  @CalledByNative
+  static void invokeValueCallbackInt(ValueCallback callback, int value) {
+      callback.onReceiveValue(value);
+  }
+}