[Android WebAPK] Enable Lightweight First Run Experience for unbound WebAPKs

This CL is a follow up to
https://chromium-review.googlesource.com/c/563885/ and enables the Lightweight First Run Experience for unbound WebAPKs by default.

The CL removes the --enable-lightweight-fre command line flag

BUG=738133

Change-Id: I7e120e7d25af0fd0d611bf9954285ca337ba4381
Reviewed-on: https://chromium-review.googlesource.com/578489Reviewed-by: Ted Choc <tedchoc@chromium.org>
Commit-Queue: Peter Kotwicz <pkotwicz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488242}

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

@@ -31,9 +31,6 @@ public abstract class ChromeSwitches {
     /** Disable the First Run Experience. */
     public static final String DISABLE_FIRST_RUN_EXPERIENCE = "disable-fre";
 
-    /** Enable the Lightweight First Run Experience. */
-    public static final String ENABLE_LIGHTWEIGHT_FIRST_RUN_EXPERIENCE = "enable-lightweight-fre";
-
     /** Force the crash dump to be uploaded regardless of preferences. */
     public static final String FORCE_CRASH_DUMP_UPLOAD = "force-dump-upload";
 

chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunFlowSequencer.java

@@ -279,9 +279,7 @@ public abstract class FirstRunFlowSequencer  {
 
         final boolean baseFreComplete = FirstRunStatus.getFirstRunFlowComplete();
         if (!baseFreComplete) {
-            if (preferLightweightFre
-                    && CommandLine.getInstance().hasSwitch(
-                               ChromeSwitches.ENABLE_LIGHTWEIGHT_FIRST_RUN_EXPERIENCE)) {
+            if (preferLightweightFre) {
                 if (!FirstRunStatus.shouldSkipWelcomePage()
                         && !FirstRunStatus.getLightweightFirstRunFlowComplete()) {
                     return createLightweightFirstRunIntent(context, fromChromeIcon);