Add support to previews/ for Server LoFi and LitePages

components/previews/core/previews_experiments.cc

 // Copyright 2016 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.
 
 #include "components/previews/core/previews_experiments.h"
 
-#include <string>
-
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/field_trial_params.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 
 namespace previews {
 
 namespace {
 
@@ skipping 147 matching lines @@
 
 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);
 }
 
+std::string GetStringNameForType(PreviewsType type) {
+  switch (type) {
+    case PreviewsType::OFFLINE:
+      return "Offline";
+    case PreviewsType::CLIENT_LOFI:
+      return "ClientLoFi";
+    case PreviewsType::SERVER_LOFI:
+      return "LoFi";
+    case PreviewsType::LITE_PAGE:
+      return "LitePage";
+    case PreviewsType::NONE:
+    case PreviewsType::LAST:
+      break;
+  }
+  NOTREACHED();
+  return std::string();
+}
+
 }  // namespace previews