Add a way to reset cached command line arguments

chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java

Index: chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java b/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
index 5db7fba026575fab99d2ead1347a0cfe64f3e1ea..b32c299cf10aec82394ebcbaf4f97c3cef09a69e 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/util/FeatureUtilities.java
@@ -33,6 +33,8 @@
     private static Boolean sHasGoogleAccountAuthenticator;
     private static Boolean sHasRecognitionIntentHandler;
     private static Boolean sDocumentModeDisabled;
+    /** Used to track if cached command line flags should be refreshed. */
+    private static CommandLine.ResetListener sResetListener = null;
 
     /**
      * Determines whether or not the {@link RecognizerIntent#ACTION_WEB_SEARCH} {@link Intent}
@@ -97,6 +99,7 @@ private static boolean hasSyncPermissions(Context context) {
      */
     public static boolean isDocumentMode(Context context) {
         if (sDocumentModeDisabled == null && CommandLine.isInitialized()) {
+            initResetListener();
             sDocumentModeDisabled = CommandLine.getInstance().hasSwitch(
                     ChromeSwitches.DISABLE_DOCUMENT_MODE);
         }
@@ -139,6 +142,18 @@ public static boolean getCustomTabVisible() {
         return nativeGetCustomTabVisible();
     }
 
+    private static void initResetListener() {
+        if (sResetListener != null) return;
+
+        sResetListener = new CommandLine.ResetListener() {
+            @Override
+            public void onCommandLineReset() {
+                sDocumentModeDisabled = null;
+            }
+        };
+        CommandLine.addResetListener(sResetListener);
+    }
+
     private static native void nativeSetDocumentModeEnabled(boolean enabled);
     private static native void nativeSetCustomTabVisible(boolean visible);
     private static native boolean nativeGetCustomTabVisible();