Show client placeholders for Server LoFi images.

content/child/runtime_features.cc

Index: content/child/runtime_features.cc
diff --git a/content/child/runtime_features.cc b/content/child/runtime_features.cc
index bd7a5864dc2b65837835d67eaeb75cd9d5ae1532..b08240054279f48d1b7dbf2d16567d23c8dcaa04 100644
--- a/content/child/runtime_features.cc
+++ b/content/child/runtime_features.cc
@@ -9,6 +9,7 @@
 #include "base/command_line.h"
 #include "base/feature_list.h"
 #include "base/metrics/field_trial.h"
+#include "base/metrics/field_trial_params.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "build/build_config.h"
@@ -391,6 +392,10 @@ void SetRuntimeFeaturesDefaultsAndUpdateFromArgs(
   WebRuntimeFeatures::EnableLocationHardReload(
       base::FeatureList::IsEnabled(features::kLocationHardReload));
 
+  WebRuntimeFeatures::EnableClientPlaceholdersForServerLoFi(
+      base::GetFieldTrialParamValue("PreviewsClientLoFi",
+                                    "replace_server_placeholders") == "true");
+
   // Enable explicitly enabled features, and then disable explicitly disabled
   // ones.
   if (command_line.HasSwitch(switches::kEnableBlinkFeatures)) {