Add new limits for extra field, updated test file.

Bug: 775160
Change-Id: Ic0f2a818386c78cf7b610035f7841f08e5477ab9
Reviewed-on: https://chromium-review.googlesource.com/723783
Reviewed-by: Peter Kotwicz <[email protected]>
Commit-Queue: Scott Kirkwood <[email protected]>
Cr-Commit-Position: refs/heads/master@{#509491}

Author: Scott Kirkwood

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

@@ -83,8 +83,9 @@ public class WebApkVerifySignature {
     /** Maximum file comment length permitted. */
     private static final int MAX_FILE_COMMENT_LENGTH = 0;
 
-    /** Maximum extra field length permitted. */
-    private static final int MAX_EXTRA_LENGTH = 8;
+    /** Maximum extra field length permitted.
+     * Support .so alignment and a 64 bytes bytes for any extras. */
+    private static final int MAX_EXTRA_LENGTH = 4096 + 64;
 
     /** The memory buffer we are going to read the zip from. */
     private final ByteBuffer mBuffer;