Change net's predictor_tab_helper to use the new content Navigation API

testing/variations/fieldtrial_testing_config_android.json

 {
     "AndroidSessionNotifications": [
         {
             "group_name": "Disabled"
         }
     ],
     "AsyncDns": [
         {
             "group_name": "AsyncDnsA"
         },
@@ skipping 214 matching lines @@
                 "PhysicalWeb"
             ],
             "group_name": "Enabled"
         }
     ],
     "Precache": [
         {
             "group_name": "Enabled"
         }
     ],
+    "PreconnectMore": [
+        {
+            "group_name": "Enabled"

[mmenke, 2016/03/18 19:26:03]

Shouldn't we have multiple groups here?

[Charlie Harrison, 2016/03/18 21:38:17]

...yes. Done.

+        }
+    ],
     "ProgressBarAnimationAndroid": [
         {
             "group_name": "SmoothAnimation",
             "params": {
                 "progress-bar-animation": "smooth"
             }
         }
     ],
     "QUIC": [
         {
@@ skipping 213 matching lines @@
     ],
     "use-new-media-cache": [
         {
             "enable_features": [
                 "use-new-media-cache"
             ],
             "group_name": "Enabled"
         }
     ]
 }