[android_webview] Add a zoomBy method to AwContents.

android_webview/javatests/src/org/chromium/android_webview/test/AwContentsClientOnScaleChangedTest.java

 // Copyright 2012 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.test;
 
+import android.test.suitebuilder.annotation.SmallTest;
+
 import org.chromium.android_webview.AwContents;
 import org.chromium.android_webview.test.util.CommonResources;
-import org.chromium.base.test.util.DisabledTest;
 import org.chromium.content.browser.ContentViewCore;
 
 /**
  * Tests for the WebViewClient.onScaleChanged.
  */
 public class AwContentsClientOnScaleChangedTest extends AwTestBase {
     private TestAwContentsClient mContentsClient;
     private AwContents mAwContents;
 
     @Override
     protected void setUp() throws Exception {
         super.setUp();
         mContentsClient = new TestAwContentsClient();
         AwTestContainerView testContainerView =
                 createAwTestContainerViewOnMainSync(mContentsClient);
         mAwContents = testContainerView.getAwContents();
     }
 
     @Override
     protected void tearDown() throws Exception {
         super.tearDown();
     }
 
-    /*
     @SmallTest
-    This test is timing out on ICS bots including cq. See crbug.com/175854.
-    */
-    @DisabledTest
     public void testScaleUp() throws Throwable {
         getAwSettingsOnUiThread(mAwContents).setUseWideViewPort(true);
         loadDataSync(mAwContents, mContentsClient.getOnPageFinishedHelper(),
                 CommonResources.ABOUT_HTML, "text/html", false);
         ContentViewCore core = mAwContents.getContentViewCore();
         int callCount = mContentsClient.getOnScaleChangedHelper().getCallCount();
         core.onSizeChanged(
                 core.getViewportWidthPix() / 2, core.getViewportHeightPix() / 2,
                 core.getViewportWidthPix(), core.getViewportHeightPix());
         // TODO: Investigate on using core.zoomIn();
         mContentsClient.getOnScaleChangedHelper().waitForCallback(callCount);
         assertTrue("Scale ratio:" + mContentsClient.getOnScaleChangedHelper().getLastScaleRatio(),
                 mContentsClient.getOnScaleChangedHelper().getLastScaleRatio() < 1);
     }
 }