Make Android Clipboard Keep Track of Last Modified Time

base/android/java/src/org/chromium/base/metrics/RecordUserAction.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.base.metrics;
 
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.JNINamespace;
 
 /**
  * Java API for recording UMA actions.
  *
  * WARNINGS:
  * JNI calls are relatively costly - avoid using in performance-critical code.
  *
  * We use a script (extract_actions.py) to scan the source code and extract actions. A string
  * literal (not a variable) must be passed to record().
  */
 @JNINamespace("base::android")
 public class RecordUserAction {
+    private static Throwable sDisabledBy;
+
+    /**
+     * Tests may not have native initialized, so they may need to disable metrics. The value should
+     * be reset after the test done, to avoid carrying over state to unrelated tests.
+     */
+    @VisibleForTesting
+    public static void setDisabledForTests(boolean disabled) {
+        if (disabled && sDisabledBy != null) {
+            throw new IllegalStateException("UserActions are already disabled.", sDisabledBy);
+        }
+        sDisabledBy = disabled ? new Throwable() : null;
+    }
+
     public static void record(final String action) {
+        if (sDisabledBy != null) return;
+
         if (ThreadUtils.runningOnUiThread()) {
             nativeRecordUserAction(action);
             return;
         }
 
         ThreadUtils.runOnUiThread(new Runnable() {
             @Override
             public void run() {
                 nativeRecordUserAction(action);
             }
         });
     }
 
     private static native void nativeRecordUserAction(String action);
 }