Fix Java Checkstyle issues.

components/cronet/android/java/src/org/chromium/net/HttpUrlRequestFactoryConfig.java

 // Copyright 2014 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.net;
 
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ skipping 107 matching lines @@
                 quicHints = new JSONArray();
                 mConfig.put(UrlRequestContextConfig.QUIC_HINTS, quicHints);
             }
 
             JSONObject hint = new JSONObject();
             hint.put(UrlRequestContextConfig.QUIC_HINT_HOST, host);
             hint.put(UrlRequestContextConfig.QUIC_HINT_PORT, port);
             hint.put(UrlRequestContextConfig.QUIC_HINT_ALT_PORT, alternatePort);
             quicHints.put(hint);
         } catch (JSONException e) {
-            ;
+            // Intentionally do nothing.
         }
         return this;
     }
 
     /**
      * Get JSON string representation of the config.
      */
+    @Override
     public String toString() {
         return mConfig.toString();
     }
 
     /**
      * Sets a boolean value in the config. Returns a reference to the same
      * config object, so you can chain put calls together.
      */
     private HttpUrlRequestFactoryConfig putBoolean(String key, boolean value) {
         try {
             mConfig.put(key, value);
         } catch (JSONException e) {
-            ;
+            // Intentionally do nothing.
         }
         return this;
     }
 
     /**
      * Sets a long value in the config. Returns a reference to the same
      * config object, so you can chain put calls together.
      */
     private HttpUrlRequestFactoryConfig putLong(String key, long value)  {
         try {
             mConfig.put(key, value);
         } catch (JSONException e) {
-            ;
+            // Intentionally do nothing.
         }
         return this;
     }
 
     /**
      * Sets a string value in the config. Returns a reference to the same
      * config object, so you can chain put calls together.
      */
     private HttpUrlRequestFactoryConfig putString(String key, String value) {
         try {
             mConfig.put(key, value);
         } catch (JSONException e) {
-            ;
+            // Intentionally do nothing.
         }
         return this;
     }
 
     private JSONObject mConfig = new JSONObject();
 }