Prefetch must not run on cellular until the user can disable

chrome/browser/prefetch/prefetch.cc

Index: chrome/browser/prefetch/prefetch.cc
diff --git a/chrome/browser/prefetch/prefetch.cc b/chrome/browser/prefetch/prefetch.cc
index 84b517b87e594c1f830e62ac7122cff9c696184b..74c39b209e5cead587fb6d434cb96dfd786c41bf 100644
--- a/chrome/browser/prefetch/prefetch.cc
+++ b/chrome/browser/prefetch/prefetch.cc
@@ -19,9 +19,17 @@ bool IsPrefetchEnabled(content::ResourceContext* resource_context) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 
   ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
-
   DCHECK(io_data);
 
+  // TODO(bnc): Remove this condition once the new
+  // predictive preference is used on all platforms. See crbug.com/334602.
+  if (io_data->network_prediction_options()->GetValue() ==
+          chrome_browser_net::NETWORK_PREDICTION_UNSET &&
+      net::NetworkChangeNotifier::IsConnectionCellular(
+          net::NetworkChangeNotifier::GetConnectionType())) {
+    return false;
+  }
+
   return chrome_browser_net::CanPredictNetworkActionsIO(io_data) &&
          !DisableForFieldTrial();
 }