✈ Remove unnecessary flag and DocumentModeManager.

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 5b6866f7c396ab0dd81da54b72a0aca0d7ddbb8c..5da08c4d6ba260d41ef26446cb1e43b2313d4ed1 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
@@ -28,7 +28,7 @@ import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeVersionInfo;
 import org.chromium.chrome.browser.preferences.ChromePreferenceManager;
-import org.chromium.chrome.browser.preferences.DocumentModeManager;
+import org.chromium.chrome.browser.tabmodel.DocumentModeAssassin;
 import org.chromium.sync.signin.AccountManagerHelper;
 import org.chromium.ui.base.DeviceFormFactor;
 
@@ -115,14 +115,8 @@ public class FeatureUtilities {
      * @return Whether Chrome should be running on document mode.
      */
     public static boolean isDocumentMode(Context context) {
-        if (sDocumentModeDisabled == null && CommandLine.isInitialized()) {
-            initResetListener();
-            sDocumentModeDisabled = CommandLine.getInstance().hasSwitch(
-                    ChromeSwitches.DISABLE_DOCUMENT_MODE);
-        }
-        return isDocumentModeEligible(context)
-                && !DocumentModeManager.getInstance(context).isOptedOutOfDocumentMode()
-                && (sDocumentModeDisabled == null || !sDocumentModeDisabled.booleanValue());
+        // isOptedOutOfDocumentMode is true by default.

[gone, 2016/05/25 18:26:05]

This comment is correct in the current state but misleading.  Just remove the
comment.

[Peter Wen, 2016/05/26 16:17:55]

Done.

+        return isDocumentModeEligible(context) && !DocumentModeAssassin.isOptedOutOfDocumentMode();
     }
 
     /**
@@ -188,18 +182,6 @@ public class FeatureUtilities {
                 ChromeSwitches.ENABLE_TAB_SWITCHER_IN_DOCUMENT_MODE);
     }
 
-    private static void initResetListener() {
-        if (sResetListener != null) return;
-
-        sResetListener = new CommandLine.ResetListener() {
-            @Override
-            public void onCommandLineReset() {
-                sDocumentModeDisabled = null;
-            }
-        };
-        CommandLine.addResetListener(sResetListener);
-    }
-
     private static boolean isHerbDisallowed(Context context) {
         return isDocumentMode(context) || ChromeVersionInfo.isStableBuild()
                 || ChromeVersionInfo.isBetaBuild() || DeviceFormFactor.isTablet(context);