Catch java.lang.IllegalArgumentException in parsing baae64

BUG=829628

Change-Id: I054c8a40cf065d0c2f42bd8de9e5de6fed3fb9e9
Reviewed-on: https://chromium-review.googlesource.com/1059155
Commit-Queue: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561876}

components/sync/android/java/src/org/chromium/components/sync/notifier/InvalidationPreferences.java

@@ -176,7 +176,11 @@ public class InvalidationPreferences {
         if (base64State == null) {
             return null;
         }
-        return Base64.decode(base64State, Base64.DEFAULT);
+        try {
+            return Base64.decode(base64State, Base64.DEFAULT);
+        } catch (java.lang.IllegalArgumentException e) {
+            return null;
+        }
     }
 
     /** Sets the notification client internal state to {@code state}. */