Added test support to observe and verify UMA user actions during tests.

base/test/user_action_tester_unittest.cc

+// 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.
+
+#include "base/test/user_action_tester.h"
+
+#include "base/metrics/user_metrics.h"
+#include "base/metrics/user_metrics_action.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+namespace {
+
+const char kUserAction1[] = "user.action.1";
+const char kUserAction2[] = "user.action.2";
+const char kUserAction3[] = "user.action.3";
+
+// Record an action and cause all ActionCallback observers to be notified.
+void RecordAction(const char user_action[]) {
+  base::RecordAction(base::UserMetricsAction(user_action));

[Ilya Sherman, 2015/04/09 23:49:35]

Could you please run tools/metrics/actions/extract_actions.py and verify whether
it outputs a warning for this call to base::RecordAction with a non-literal
string?

[bruthig, 2015/04/10 00:05:26]

Verified, no Warning output.

+}
+
+}  // namespace
+
+// Verify user action counts are zero initially.
+TEST(UserActionTesterTest, GetActionCountWhenNoActionsHaveBeenRecorded) {
+  UserActionTester user_action_tester;
+  EXPECT_EQ(0, user_action_tester.GetActionCount(kUserAction1));
+}
+
+// Verify user action counts are tracked properly.
+TEST(UserActionTesterTest, GetActionCountWhenActionsHaveBeenRecorded) {
+  UserActionTester user_action_tester;
+
+  RecordAction(kUserAction1);
+  RecordAction(kUserAction2);
+  RecordAction(kUserAction2);
+
+  EXPECT_EQ(1, user_action_tester.GetActionCount(kUserAction1));
+  EXPECT_EQ(2, user_action_tester.GetActionCount(kUserAction2));
+  EXPECT_EQ(0, user_action_tester.GetActionCount(kUserAction3));
+}
+
+// Verify no seg faults occur when resetting action counts when none have been
+// recorded.
+TEST(UserActionTesterTest, ResetCountsWhenNoActionsHaveBeenRecorded) {
+  UserActionTester user_action_tester;
+  user_action_tester.ResetCounts();
+}
+
+// Verify user action counts are set to zero on a ResetCounts.
+TEST(UserActionTesterTest, ResetCountsWhenActionsHaveBeenRecorded) {
+  UserActionTester user_action_tester;
+
+  RecordAction(kUserAction1);
+  RecordAction(kUserAction1);
+  RecordAction(kUserAction2);
+  user_action_tester.ResetCounts();
+
+  EXPECT_EQ(0, user_action_tester.GetActionCount(kUserAction1));
+  EXPECT_EQ(0, user_action_tester.GetActionCount(kUserAction2));
+  EXPECT_EQ(0, user_action_tester.GetActionCount(kUserAction3));
+}
+
+// Verify the UserActionsTester is notified when base::RecordAction is called.
+TEST(UserActionTesterTest, VerifyUserActionTesterListensForUserActions) {
+  UserActionTester user_action_tester;
+
+  base::RecordAction(base::UserMetricsAction(kUserAction1));
+
+  EXPECT_EQ(1, user_action_tester.GetActionCount(kUserAction1));
+}
+
+// Verify the UserActionsTester is notified when base::RecordComputedAction is
+// called.
+TEST(UserActionTesterTest,
+     VerifyUserActionTesterListensForComputedUserActions) {
+  UserActionTester user_action_tester;
+
+  base::RecordComputedAction(kUserAction1);
+
+  EXPECT_EQ(1, user_action_tester.GetActionCount(kUserAction1));
+}
+
+}  // namespace base