[Android WebView] Fix some findbugs warnings.

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

 // Copyright (c) 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.os.Bundle;
 import android.os.SystemClock;
 import android.test.suitebuilder.annotation.SmallTest;
 import android.util.Pair;
@@ skipping 27 matching lines @@
     private final static String DATA_URL = "data:text/html,<div/>";
     private final static String REDIRECT_TARGET_PATH = "/redirect_target.html";
     private final static String TITLE = "TITLE";
 
     private static final long TEST_TIMEOUT = 20000L;
     private static final int CHECK_INTERVAL = 100;
 
     private static class TestAwContentsClient
             extends org.chromium.android_webview.test.TestAwContentsClient {
 
-        public class ShouldIgnoreNavigationHelper extends CallbackHelper {
+        public static class ShouldIgnoreNavigationHelper extends CallbackHelper {
             private String mShouldIgnoreNavigationUrl;
             private String mPreviousShouldIgnoreNavigationUrl;
             private boolean mShouldIgnoreNavigationReturnValue = false;
             void setShouldIgnoreNavigationUrl(String url) {
                 mShouldIgnoreNavigationUrl = url;
             }
             void setPreviousShouldIgnoreNavigationUrl(String url) {
                 mPreviousShouldIgnoreNavigationUrl = url;
             }
             void setShouldIgnoreNavigationReturnValue(boolean value) {
@@ skipping 695 matching lines @@
             final String redirectTargetUrl = createRedirectTargetPage(webServer);
             final String redirectUrl = addPageToTestServer(webServer, "/js_delayed_replace.html",
                     getHtmlForPageWithJsRedirectTo(redirectTargetUrl, "Replace", 100));
             doTestShouldIgnoreNavigationCalledOnRedirect(webServer, redirectUrl,
                     redirectTargetUrl);
         } finally {
             if (webServer != null) webServer.shutdown();
         }
     }
 }