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

There are currently a few custom user action observers to record and verify
UMA user actions during tests.  This patch adds that support to a common location.

TEST=UserActionTesterTest.GetActionCountWhenNoActionsHaveBeenRecorded
TEST=UserActionTesterTest.GetActionCountWhenActionsHaveBeenRecorded
TEST=UserActionTesterTest.ResetCountsWhenNoActionsHaveBeenRecorded
TEST=UserActionTesterTest.ResetCountsWhenActionsHaveBeenRecorded
TEST=UserActionTesterTest.VerifyUserActionTesterListensForUserActions

BUG=475181

Review URL: https://codereview.chromium.org/1073613002

Cr-Commit-Position: refs/heads/master@{#324953}

6 files changed, 173 insertions, 0 deletions

diff --git a/base/BUILD.gn b/base/BUILD.gn
index 6223378..b9f134e 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1250,6 +1250,7 @@ test("base_unittests") {
     "test/histogram_tester_unittest.cc",
     "test/test_reg_util_win_unittest.cc",
     "test/trace_event_analyzer_unittest.cc",
+    "test/user_action_tester_unittest.cc",
     "threading/non_thread_safe_unittest.cc",
     "threading/platform_thread_unittest.cc",
     "threading/sequenced_worker_pool_unittest.cc",
diff --git a/base/base.gyp b/base/base.gyp
index bea8bc9..b9362b4 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -632,6 +632,7 @@
         'test/test_pending_task_unittest.cc',
         'test/test_reg_util_win_unittest.cc',
         'test/trace_event_analyzer_unittest.cc',
+        'test/user_action_tester_unittest.cc',
         'threading/non_thread_safe_unittest.cc',
         'threading/platform_thread_unittest.cc',
         'threading/sequenced_worker_pool_unittest.cc',
@@ -1010,6 +1011,8 @@
         'test/trace_event_analyzer.h',
         'test/trace_to_file.cc',
         'test/trace_to_file.h',
+        'test/user_action_tester.cc',
+        'test/user_action_tester.h',
         'test/values_test_util.cc',
         'test/values_test_util.h',
       ],
diff --git a/base/test/BUILD.gn b/base/test/BUILD.gn
index 6872aff..8baeb14 100644
--- a/base/test/BUILD.gn
+++ b/base/test/BUILD.gn
@@ -116,6 +116,8 @@ source_set("test_support") {
     "trace_event_analyzer.h",
     "trace_to_file.cc",
     "trace_to_file.h",
+    "user_action_tester.cc",
+    "user_action_tester.h",
     "values_test_util.cc",
     "values_test_util.h",
   ]
diff --git a/base/test/user_action_tester.cc b/base/test/user_action_tester.cc
new file mode 100644
index 0000000..3fdab12
--- /dev/null
+++ b/base/test/user_action_tester.cc
@@ -0,0 +1,35 @@
+// 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/bind.h"
+#include "base/bind_helpers.h"
+
+namespace base {
+
+UserActionTester::UserActionTester()
+    : action_callback_(
+          base::Bind(&UserActionTester::OnUserAction, base::Unretained(this))) {
+  base::AddActionCallback(action_callback_);
+}
+
+UserActionTester::~UserActionTester() {
+  base::RemoveActionCallback(action_callback_);
+}
+
+int UserActionTester::GetActionCount(const std::string& user_action) const {
+  UserActionCountMap::const_iterator iter = count_map_.find(user_action);
+  return iter == count_map_.end() ? 0 : iter->second;
+}
+
+void UserActionTester::ResetCounts() {
+  count_map_.clear();
+}
+
+void UserActionTester::OnUserAction(const std::string& user_action) {
+  ++(count_map_[user_action]);
+}
+
+}  // namespace base
diff --git a/base/test/user_action_tester.h b/base/test/user_action_tester.h
new file mode 100644
index 0000000..6b0efc5
--- /dev/null
+++ b/base/test/user_action_tester.h
@@ -0,0 +1,46 @@
+// 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.
+
+#ifndef BASE_TEST_USER_ACTION_TESTER_H_
+#define BASE_TEST_USER_ACTION_TESTER_H_
+
+#include <map>
+#include <string>
+
+#include "base/metrics/user_metrics.h"
+
+namespace base {
+
+// This class observes and collects user action notifications that are sent
+// by the tests, so that they can be examined afterwards for correctness.
+// Note: This class is NOT thread-safe.
+class UserActionTester {
+ public:
+  UserActionTester();
+  ~UserActionTester();
+
+  // Returns the number of times the given |user_action| occurred.
+  int GetActionCount(const std::string& user_action) const;
+
+  // Resets all user action counts to 0.
+  void ResetCounts();
+
+ private:
+  typedef std::map<std::string, int> UserActionCountMap;
+
+  // The callback that is notified when a user actions occurs.
+  void OnUserAction(const std::string& user_action);
+
+  // A map that tracks the number of times a user action has occurred.
+  UserActionCountMap count_map_;
+
+  // The callback that is added to the global action callback list.
+  base::ActionCallback action_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserActionTester);
+};
+
+}  // namespace base
+
+#endif  // BASE_TEST_USER_ACTION_TESTER_H_
diff --git a/base/test/user_action_tester_unittest.cc b/base/test/user_action_tester_unittest.cc
new file mode 100644
index 0000000..a51849f
--- /dev/null
+++ b/base/test/user_action_tester_unittest.cc
@@ -0,0 +1,86 @@
+// 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));
+}
+
+}  // 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