Introduce chrome://flags/#network-prediction-options-for-service-worker

chrome/browser/net/prediction_options.cc

Index: chrome/browser/net/prediction_options.cc
diff --git a/chrome/browser/net/prediction_options.cc b/chrome/browser/net/prediction_options.cc
index 8ab8a07cd54fd9048219b43491fc8db7758eb76c..ab0f70ae06b1e9ed216fbfe98ebee00bf5ec4d0e 100644
--- a/chrome/browser/net/prediction_options.cc
+++ b/chrome/browser/net/prediction_options.cc
@@ -4,8 +4,11 @@
 
 #include "chrome/browser/net/prediction_options.h"
 
+#include "base/command_line.h"
 #include "base/logging.h"
+#include "base/metrics/field_trial.h"
 #include "chrome/browser/profiles/profile_io_data.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "components/prefs/pref_service.h"
@@ -14,6 +17,13 @@
 
 namespace chrome_browser_net {
 
+const char kPreconnectOnly[] = "PreconnectOnly";
+const char kStartServiceWorkerAndPreconnect[] =
+    "StartServiceWorkerAndPreconnect";
+const char kStartServiceWorkerAndDeferPreconnect[] =
+    "StartServiceWorkerAndDeferPreconnect";
+const char kStartServiceWorkerOnly[] = "StartServiceWorkerOnly";
+
 namespace {
 
 // Since looking up preferences and current network connection are presumably
@@ -80,4 +90,30 @@ bool CanPreresolveAndPreconnectUI(PrefService* prefs) {
       prefs->GetInteger(prefs::kNetworkPredictionOptions));
 }
 
+NetworkPredictionOptionsForServiceWorker
+GetNetworkPredictionOptionsForServiceWorker() {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  std::string options = command_line.GetSwitchValueASCII(
+      switches::kNetworkPredictionOptionsForServiceWorker);
+  if (options.empty()) {
+    options = base::FieldTrialList::FindFullName(
+        "NetworkPredictionOptionsForServiceWorker");
+  }
+
+  if (options == kPreconnectOnly) {
+    return NetworkPredictionOptionsForServiceWorker::PRECONNECT_ONLY;
+  } else if (options == kStartServiceWorkerAndPreconnect) {
+    return NetworkPredictionOptionsForServiceWorker::
+        START_SERVICE_WORKER_AND_PRECONNECT;
+  } else if (options == kStartServiceWorkerAndDeferPreconnect) {
+    return NetworkPredictionOptionsForServiceWorker::
+        START_SERVICE_WORKER_AND_DEFER_PRECONNECT;
+  } else if (options == kStartServiceWorkerOnly) {
+    return NetworkPredictionOptionsForServiceWorker::START_SERVICE_WORKER_ONLY;
+  } else {
+    return NetworkPredictionOptionsForServiceWorker::PRECONNECT_ONLY;
+  }
+}
+
 }  // namespace chrome_browser_net