Check AllowStartingServiceManagerOnly in ServiceManagerStartupUtils.

AllowStartingServiceManagerOnly already gates starting the service
manager early in the native code. Make the Java code check the flag
too.

Bug: 899225,899226
Change-Id: Iadc7d03b4e3b559815a72de66ff249f2ad36bbbb
Reviewed-on: https://chromium-review.googlesource.com/c/1318362Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Xi Han <hanxi@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612380}

chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java

@@ -149,6 +149,8 @@ public abstract class ChromeFeatureList {
     // Alphabetical:
     public static final String ALLOW_REMOTE_CONTEXT_FOR_NOTIFICATIONS =
             "AllowRemoteContextForNotifications";
+    public static final String ALLOW_STARTING_SERVICE_MANAGER_ONLY =
+            "AllowStartingServiceManagerOnly";
     public static final String AUTOFILL_ALLOW_NON_HTTP_ACTIVATION =
             "AutofillAllowNonHttpActivation";
     public static final String ADJUST_WEBAPK_INSTALLATION_SPACE = "AdjustWebApkInstallationSpace";

chrome/android/java/src/org/chromium/chrome/browser/init/ServiceManagerStartupUtils.java

@@ -21,9 +21,13 @@ import java.util.Set;
 public class ServiceManagerStartupUtils {
     public static final String TASK_TAG = "Servicification Startup Task";
 
+    // Master flag that gates all features that depend on starting the service manager early.
+    private static final String EARLY_START_FLAG =
+            ChromeFeatureList.ALLOW_STARTING_SERVICE_MANAGER_ONLY;
+
     // List of features that supports starting ServiceManager on startup.
     private static final String[] SERVICE_MANAGER_FEATURES = {
-            ChromeFeatureList.SERVICE_MANAGER_FOR_DOWNLOAD};
+            EARLY_START_FLAG, ChromeFeatureList.SERVICE_MANAGER_FOR_DOWNLOAD};
     // Key in the SharedPreferences for storing all features that will start ServiceManager.
     private static final String SERVICE_MANAGER_FEATURES_KEY = "ServiceManagerFeatures";
 
@@ -35,7 +39,8 @@ public class ServiceManagerStartupUtils {
     public static boolean canStartServiceManager(String featureName) {
         Set<String> features = ContextUtils.getAppSharedPreferences().getStringSet(
                 SERVICE_MANAGER_FEATURES_KEY, null);
-        return features != null && features.contains(featureName);
+        return features != null && features.contains(EARLY_START_FLAG)
+                && features.contains(featureName);
     }
 
     /**

chrome/browser/android/chrome_feature_list.cc

@@ -56,6 +56,7 @@ const base::Feature* kFeaturesExposedToJava[] = {
     &contextual_suggestions::kContextualSuggestionsButton,
     &contextual_suggestions::kContextualSuggestionsIPHReverseScroll,
     &contextual_suggestions::kContextualSuggestionsOptOut,
+    &features::kAllowStartingServiceManagerOnly,
     &features::kAppNotificationStatusMessaging,
     &features::kClearOldBrowsingData,
     &features::kClipboardContentSetting,

content/app/content_main_runner_impl.cc

@@ -172,11 +172,6 @@ namespace content {
 
 namespace {
 
-#if !defined(CHROME_MULTIPLE_DLL_CHILD)
-const char kAllowStartingServiceManagerOnly[] =
-    "allow-start-service-manager-only";
-#endif
-
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA) && defined(OS_ANDROID)
 #if defined __LP64__
 #define kV8SnapshotDataDescriptor kV8Snapshot64DataDescriptor
@@ -932,8 +927,8 @@ int ContentMainRunnerImpl::RunServiceManager(MainFunctionParams& main_params,
 #endif
   }
 
-  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
-          kAllowStartingServiceManagerOnly) &&
+  if (base::FeatureList::IsEnabled(
+          features::kAllowStartingServiceManagerOnly) &&
       start_service_manager_only) {
     return -1;
   }

content/public/common/content_features.cc

@@ -18,6 +18,10 @@ namespace features {
 const base::Feature kAllowActivationDelegationAttr{
     "AllowActivationDelegationAttr", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Allows starting services without the browser process.
+const base::Feature kAllowStartingServiceManagerOnly{
+    "AllowStartingServiceManagerOnly", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables content-initiated, main frame navigations to data URLs.
 // TODO(meacer): Remove when the deprecation is complete.
 //               https://www.chromestatus.com/feature/5669602927312896

content/public/common/content_features.h

@@ -17,6 +17,7 @@ namespace features {
 // All features in alphabetical order. The features should be documented
 // alongside the definition of their values in the .cc file.
 CONTENT_EXPORT extern const base::Feature kAllowActivationDelegationAttr;
+CONTENT_EXPORT extern const base::Feature kAllowStartingServiceManagerOnly;
 CONTENT_EXPORT extern const base::Feature
     kAllowContentInitiatedDataUrlNavigations;
 CONTENT_EXPORT extern const base::Feature