Adds unit tests for AwContentsClientCallbackHelper

android_webview/java/src/org/chromium/android_webview/AwContentsClientCallbackHelper.java

 // 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;
 
 import android.graphics.Picture;
 import android.os.Handler;
 import android.os.Looper;
 import android.os.Message;
 import android.os.SystemClock;
 
+import com.google.common.annotations.VisibleForTesting;
+
 import java.util.concurrent.Callable;
 
 /**
  * This class is responsible for calling certain client callbacks on the UI thread.
  *
  * Most callbacks do no go through here, but get forwarded to AwContentsClient directly. The
  * messages processed here may originate from the IO or UI thread.
  */
-class AwContentsClientCallbackHelper {
+@VisibleForTesting
+public class AwContentsClientCallbackHelper {
 
     // TODO(boliu): Consider removing DownloadInfo and LoginRequestInfo by using native
     // MessageLoop to post directly to AwContents.
 
     private static class DownloadInfo {
         final String mUrl;
         final String mUserAgent;
         final String mContentDisposition;
         final String mMimeType;
         final long mContentLength;
@@ skipping 155 matching lines @@
 
     public void postOnScaleChangedScaled(float oldScale, float newScale) {
         // The float->int->float conversion here is to avoid unnecessary allocations. The
         // documentation states that intBitsToFloat(floatToIntBits(a)) == a for all values of a
         // (except for NaNs which are collapsed to a single canonical NaN, but we don't care for
         // that case).
         mHandler.sendMessage(mHandler.obtainMessage(MSG_ON_SCALE_CHANGED_SCALED,
                     Float.floatToIntBits(oldScale), Float.floatToIntBits(newScale)));
     }
 }