Fix bug in one conditional. Add more apk test files.

chrome/android/webapk/libs/client/junit/src/org/chromium/webapk/lib/client/WebApkValidatorTest.java

 // Copyright 2016 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.webapk.lib.client;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
@@ skipping 211 matching lines @@
      * Tests {@link WebApkValidator#isValidWebApk()} for failing comment signed webapks.
      * These  WebAPKs were modified to fail in specific ways.
      */
     @Test
     public void testIsValidWebApkCommentSignedFailures() {
         String[] filenames = {
                 "bad-sig.apk", "bad-utf8-fname.apk", "empty.apk", "extra-field-too-large.apk",
                 "extra-len-too-large.apk", "fcomment-too-large.apk", "no-cd.apk", "no-comment.apk",
                 "no-eocd.apk", "no-lfh.apk", "not-an.apk", "too-many-metainf.apk", "truncated.apk",
                 "zeros.apk", "zeros-at-end.apk", "block-before-first.apk", "block-at-end.apk",
-                "block-before-eocd.apk", "block-before-cd.apk", "v2-signed-too-large.apk",
+                "block-before-eocd.apk", "block-before-cd.apk", "block-middle.apk",
+                "v2-signed-too-large.apk",
         };
         String packageName = "com.webapk.a9c419502bb98fcb7";
         Signature[] signature = new Signature[] {new Signature(SIGNATURE_1)};
 
         for (String filename : filenames) {
             mPackageManager.removePackage(packageName);
             mPackageManager.addPackage(
                     newPackageInfo(packageName, signature, testFilePath(filename)));
             assertFalse(filename,
                     WebApkValidator.isValidWebApk(RuntimeEnvironment.application, packageName));
@@ skipping 25 matching lines @@
         return packageInfo;
     }
 
     // The browser signature is expected to always be the second signature - the first (and any
     // additional ones after the second) are ignored.
     private static PackageInfo newPackageInfoWithBrowserSignature(
             String packageName, Signature signature) {
         return newPackageInfo(packageName, new Signature[] {new Signature(""), signature}, null);
     }
 }