Test processsing latest I/O stats in CarWatchdogService.

Test: atest CarWatchdogServiceUnitTest CarWatchdogDaemonHelperTest
libwatchdog_test
Bug: 170741935
Bug: 184310189

Change-Id: I84ccb9e2463a7bface8083778138cafd6993187a
diff --git a/tests/carservice_unit_test/src/com/android/car/watchdog/ResourceOveruseStatsSubject.java b/tests/carservice_unit_test/src/com/android/car/watchdog/ResourceOveruseStatsSubject.java
new file mode 100644
index 0000000..6b7b7ba
--- /dev/null
+++ b/tests/carservice_unit_test/src/com/android/car/watchdog/ResourceOveruseStatsSubject.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.car.watchdog;
+
+import static com.google.common.truth.Truth.assertAbout;
+
+import android.annotation.Nullable;
+import android.car.watchdog.ResourceOveruseStats;
+
+import com.google.common.truth.Correspondence;
+import com.google.common.truth.FailureMetadata;
+import com.google.common.truth.Subject;
+import com.google.common.truth.Truth;
+
+import java.util.Arrays;
+
+public final class ResourceOveruseStatsSubject extends Subject {
+    // Boiler-plate Subject.Factory for ResourceOveruseStatsSubject
+    private static final Subject.Factory<com.android.car.watchdog.ResourceOveruseStatsSubject,
+            Iterable<ResourceOveruseStats>> RESOURCE_OVERUSE_STATS_SUBJECT_FACTORY =
+            com.android.car.watchdog.ResourceOveruseStatsSubject::new;
+
+    private final Iterable<ResourceOveruseStats> mActual;
+
+    // User-defined entry point
+    public static ResourceOveruseStatsSubject assertThat(
+            @Nullable Iterable<ResourceOveruseStats> stats) {
+        return assertAbout(RESOURCE_OVERUSE_STATS_SUBJECT_FACTORY).that(stats);
+    }
+
+    public static Subject.Factory<ResourceOveruseStatsSubject, Iterable<ResourceOveruseStats>>
+            resourceOveruseStats() {
+        return RESOURCE_OVERUSE_STATS_SUBJECT_FACTORY;
+    }
+
+    private ResourceOveruseStatsSubject(FailureMetadata failureMetadata,
+            @Nullable Iterable<ResourceOveruseStats> iterableSubject) {
+        super(failureMetadata, iterableSubject);
+        this.mActual = iterableSubject;
+    }
+
+    public void containsExactly(ResourceOveruseStats... stats) {
+        containsExactlyElementsIn(Arrays.asList(stats));
+    }
+
+    public void containsExactlyElementsIn(Iterable<ResourceOveruseStats> expected) {
+        Truth.assertThat(mActual)
+                .comparingElementsUsing(Correspondence.from(ResourceOveruseStatsSubject::isEquals,
+                        "is equal to"))
+                .containsExactlyElementsIn(expected);
+    }
+
+    public static boolean isEquals(ResourceOveruseStats actual, ResourceOveruseStats expected) {
+        if (actual == expected) {
+            return true;
+        }
+        if (actual == null || expected == null) {
+            return false;
+        }
+        return actual.getPackageName() == expected.getPackageName()
+                && actual.getUserHandle().equals(expected.getUserHandle())
+                && IoOveruseStatsSubject.isEquals(actual.getIoOveruseStats(),
+                    expected.getIoOveruseStats());
+    }
+}