Add tab persistence support for CustomTabs.

base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java

Index: base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java
diff --git a/base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java b/base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java
index e552fe002b5c23ef1b20f8a5ecfe6912d0b86dac..9680600d30206625b3593563109f5ade54a3c0f4 100644
--- a/base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java
+++ b/base/android/java/src/org/chromium/base/ApiCompatibilityUtils.java
@@ -44,6 +44,17 @@ public class ApiCompatibilityUtils {
     }
 
     /**
+     * @see Long#compare(long, long)
+     */
+    public static int compareLong(long lhs, long rhs) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+            return Long.compare(lhs, rhs);
+        } else {
+            return lhs < rhs ? -1 : (lhs == rhs ? 0 : 1);
+        }
+    }
+
+    /**
      * Returns true if view's layout direction is right-to-left.
      *
      * @param view the View whose layout is being considered