Add an about flag to toggle the visibility of "All bookmarks"

chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java

Index: chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java
index bf57228e3f3d7c40e22d0bd765ae0747d5389d0c..bb19840dba416ebb84b5319bf7bf9e72f0ddf947 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/bookmarks/BookmarkUtils.java
@@ -15,10 +15,12 @@ import android.provider.Browser;
 import android.text.TextUtils;
 
 import org.chromium.base.ApiCompatibilityUtils;
+import org.chromium.base.CommandLine;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.base.metrics.RecordUserAction;
 import org.chromium.chrome.R;
+import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.IntentHandler;
 import org.chromium.chrome.browser.UrlConstants;
 import org.chromium.chrome.browser.ntp.NewTabPageUma;
@@ -276,4 +278,11 @@ public class BookmarkUtils {
             ((Activity) context).finish();
         }
     }
+
+    /**
+     * @return Whether "all bookmarks" section is enabled.
+     */
+    static boolean isAllBookmarksViewEnabled() {
+        return CommandLine.getInstance().hasSwitch(ChromeSwitches.ENABLE_ALL_BOOKMARKS_VIEW);
+    }
 }