Generalize Previews Type code

components/previews/core/previews_experiments.cc

Index: components/previews/core/previews_experiments.cc
diff --git a/components/previews/core/previews_experiments.cc b/components/previews/core/previews_experiments.cc
index afd1fff87f1ee8db5d3751c94b842d02c69d94ed..2dc8e2e3f4fe637c68c398b045051f5da8b304e1 100644
--- a/components/previews/core/previews_experiments.cc
+++ b/components/previews/core/previews_experiments.cc
@@ -103,22 +103,27 @@ base::TimeDelta BlackListDuration() {
 
 bool IsIncludedInClientSidePreviewsExperimentsFieldTrial() {
   // By convention, an experiment in the client-side previews study enables use
   // of at least one client-side previews optimization if its name begins with
   // "Enabled."
   return base::StartsWith(
       base::FieldTrialList::FindFullName(kClientSidePreviewsFieldTrial),
       kEnabled, base::CompareCase::SENSITIVE);
 }
 
-bool IsOfflinePreviewsEnabled() {
-  return ParamValue(kOfflinePagesSlowNetwork) == kExperimentEnabled;
+bool IsPreviewsTypeEnabled(PreviewsType type) {
+  switch (type) {
+    case PreviewsType::OFFLINE:
+      return ParamValue(kOfflinePagesSlowNetwork) == kExperimentEnabled;
+    default:
+      return false;

[tbansal1, 2016/10/21 16:17:19]

Add NOTREACHED() in default?

+  }
 }
 
 bool EnableOfflinePreviewsForTesting() {
   std::map<std::string, std::string> params;
   params[kOfflinePagesSlowNetwork] = kExperimentEnabled;
   return variations::AssociateVariationParams(kClientSidePreviewsFieldTrial,
                                               kEnabled, params) &&
          base::FieldTrialList::CreateFieldTrial(kClientSidePreviewsFieldTrial,
                                                 kEnabled);
 }