Refactor anomaly detection

This cl refactor it so:
1. AnomayLoader could create its own BatteryStatsHelper if needed.
2. AnomalyDetector could detect the anomaly with a target package name
3. Remove FeatureProvider in AnomalyLoader and use
AnomalyDetectionPolicy instead

With this cl, we could add anomaly detection to battery usage page
more easily.

Bug: 36924669
Test: RunSettingsRoboTests
Change-Id: I1ee09701de8b5c8855f44e447813760285794c89

src/com/android/settings/fuelgauge/anomaly/AnomalyLoader.java

@@ -17,11 +17,12 @@
 package com.android.settings.fuelgauge.anomaly;
 
 import android.content.Context;
+import android.os.BatteryStats;
+import android.os.Bundle;
+import android.os.UserManager;
 import android.support.annotation.VisibleForTesting;
 
 import com.android.internal.os.BatteryStatsHelper;
-import com.android.settings.fuelgauge.PowerUsageFeatureProvider;
-import com.android.settings.overlay.FeatureFactory;
 import com.android.settings.utils.AsyncLoader;
 
 import java.util.ArrayList;
@@ -33,16 +34,45 @@ import java.util.List;
  */
 public class AnomalyLoader extends AsyncLoader<List<Anomaly>> {
     private BatteryStatsHelper mBatteryStatsHelper;
-    private PowerUsageFeatureProvider mPowerUsageFeatureProvider;
+    private String mPackageName;
+    private UserManager mUserManager;
     @VisibleForTesting
     AnomalyUtils mAnomalyUtils;
+    @VisibleForTesting
+    AnomalyDetectionPolicy mPolicy;
 
+    /**
+     * Create {@link AnomalyLoader} that runs anomaly check for all apps.
+     */
     public AnomalyLoader(Context context, BatteryStatsHelper batteryStatsHelper) {
+        this(context, batteryStatsHelper, null, new AnomalyDetectionPolicy(context));
+
+    }
+
+    /**
+     * Create {@link AnomalyLoader} with {@code packageName}, so this loader will only
+     * detect anomalies related to {@code packageName}, or check all apps if {@code packageName}
+     * is {@code null}.
+     *
+     * This constructor will create {@link BatteryStatsHelper} in background thread.
+     *
+     * @param context
+     * @param packageName if set, only finds anomalies for this package. If {@code null},
+     *                    detects all anomalies of this type.
+     */
+    public AnomalyLoader(Context context, String packageName) {
+        this(context, null, packageName, new AnomalyDetectionPolicy(context));
+    }
+
+    @VisibleForTesting
+    AnomalyLoader(Context context, BatteryStatsHelper batteryStatsHelper,
+            String packageName, AnomalyDetectionPolicy policy) {
         super(context);
         mBatteryStatsHelper = batteryStatsHelper;
-        mPowerUsageFeatureProvider = FeatureFactory.getFactory(
-                context).getPowerUsageFeatureProvider(context);
+        mPackageName = packageName;
         mAnomalyUtils = AnomalyUtils.getInstance(context);
+        mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
+        mPolicy = policy;
     }
 
     @Override
@@ -51,11 +81,18 @@ public class AnomalyLoader extends AsyncLoader<List<Anomaly>> {
 
     @Override
     public List<Anomaly> loadInBackground() {
+        if (mBatteryStatsHelper == null) {
+            mBatteryStatsHelper = new BatteryStatsHelper(getContext());
+            mBatteryStatsHelper.create((Bundle) null);
+            mBatteryStatsHelper.refreshStats(BatteryStats.STATS_SINCE_CHARGED,
+                    mUserManager.getUserProfiles());
+        }
+
         final List<Anomaly> anomalies = new ArrayList<>();
         for (@Anomaly.AnomalyType int type : Anomaly.ANOMALY_TYPE_LIST) {
-            if (mPowerUsageFeatureProvider.isAnomalyDetectorEnabled(type)) {
+            if (mPolicy.isAnomalyDetectorEnabled(type)) {
                 anomalies.addAll(mAnomalyUtils.getAnomalyDetector(type).detectAnomalies(
-                        mBatteryStatsHelper));
+                        mBatteryStatsHelper, mPackageName));
             }
         }