Make chrome://flags control whether the WebAPK feature is on

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
index 1410b7082a415b1ad461a7b6e0489717111b38e3..fa6dd93593f9e5576c226fb705294c6731a1295b 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeFeatureList.java
@@ -58,6 +58,7 @@ public abstract class ChromeFeatureList {
     public static final String CONTEXTUAL_SEARCH_SINGLE_ACTIONS = "ContextualSearchSingleActions";
     /** Whether we show an important sites dialog in the "Clear Browsing Data" flow. */
     public static final String IMPORTANT_SITES_IN_CBD = "ImportantSitesInCBD";
+    public static final String IMPROVED_A2HS = "ImprovedA2HS";
     public static final String NO_CREDIT_CARD_ABORT = "NoCreditCardAbort";
     public static final String NTP_FAKE_OMNIBOX_TEXT = "NTPFakeOmniboxText";
     public static final String NTP_FOREIGN_SESSIONS_SUGGESTIONS = "NTPForeignSessionsSuggestions";
@@ -71,7 +72,6 @@ public abstract class ChromeFeatureList {
     public static final String VR_SHELL = "VrShell";
     public static final String WEB_PAYMENTS = "WebPayments";
     public static final String WEB_PAYMENTS_MODIFIERS = "WebPaymentsModifiers";
-    public static final String WEBAPKS = "WebApks";
 
     private static native boolean nativeIsEnabled(String featureName);
 }