[android] Add JobScheduler-based BackgroundTaskScheduler.

components/background_task_scheduler/android/java/src/org/chromium/components/background_task_scheduler/BundleToPersistableBundleConverter.java

+// Copyright 2017 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.components.background_task_scheduler;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.PersistableBundle;
+import android.support.annotation.NonNull;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Converts from {@link Bundle} to {@link PersistableBundle}.
+ *
+ * The {@link android.app.job.JobScheduler} API requires the use of {@link PersistableBundle} in
+ * the {@link android.app.job.JobInfo}, but that was added in API 21 (Lollipop). A later change
+ * related to booleans means that this class required API 22 (Lollipop MR1).
+ * the API of the {@link BackgroundTaskScheduler} needs to take a {@link Bundle}, but convert it to
+ * a {@link PersistableBundle} in the case of using {@link android.app.job.JobScheduler} as the
+ * backend for scheduling.
+ */
+@TargetApi(Build.VERSION_CODES.LOLLIPOP_MR1)
+class BundleToPersistableBundleConverter {
+    /**
+     * A Result which contains the resulting {@link PersistableBundle} after a conversion, and also
+     * contains a set of all the failed keys.
+     */
+    static class Result {
+        @NonNull
+        private final PersistableBundle mBundle;
+        @NonNull
+        private final Set<String> mFailedKeys;
+
+        private Result(@NonNull PersistableBundle bundle, @NonNull Set<String> failedKeys) {
+            mBundle = bundle;
+            mFailedKeys = failedKeys;
+        }
+
+        boolean hasErrors() {
+            return mFailedKeys.size() > 0;
+        }
+
+        @NonNull
+        PersistableBundle getPersistableBundle() {
+            return mBundle;
+        }
+
+        @NonNull
+        Set<String> getFailedKeys() {
+            return mFailedKeys;
+        }
+
+        String getFailedKeysErrorString() {
+            StringBuilder sb = new StringBuilder();
+            sb.append("{");
+            boolean first = true;
+            for (String key : mFailedKeys) {
+                if (!first) sb.append(", ");
+                first = false;
+
+                sb.append(key);
+            }
+            sb.append("}");
+            return sb.toString();
+        }
+    }
+
+    /**
+     * Copy all entries in the {@link Bundle} that can be part of a {@link PersistableBundle}.
+     *
+     * @param bundle the {@link Bundle} to convert.
+     * @return a result object contain the resulting {@link PersistableBundle} and whether any of
+     *         the keys failed.
+     */
+    static Result convert(Bundle bundle) {
+        PersistableBundle persistableBundle = new PersistableBundle();
+        Set<String> failedKeys = new HashSet<>();
+        for (String key : bundle.keySet()) {
+            Object obj = bundle.get(key);
+            if (obj == null) {
+                persistableBundle.putString(key, null);
+            } else if (obj instanceof Boolean) {
+                persistableBundle.putBoolean(key, (Boolean) obj);
+            } else if (obj instanceof boolean[]) {
+                persistableBundle.putBooleanArray(key, (boolean[]) obj);
+            } else if (obj instanceof Double) {
+                persistableBundle.putDouble(key, (Double) obj);
+            } else if (obj instanceof double[]) {
+                persistableBundle.putDoubleArray(key, (double[]) obj);
+            } else if (obj instanceof Integer) {
+                persistableBundle.putInt(key, (Integer) obj);
+            } else if (obj instanceof int[]) {
+                persistableBundle.putIntArray(key, (int[]) obj);
+            } else if (obj instanceof Long) {
+                persistableBundle.putLong(key, (Long) obj);
+            } else if (obj instanceof long[]) {
+                persistableBundle.putLongArray(key, (long[]) obj);
+            } else if (obj instanceof String) {
+                persistableBundle.putString(key, (String) obj);
+            } else if (obj instanceof String[]) {
+                persistableBundle.putStringArray(key, (String[]) obj);
+            } else {
+                failedKeys.add(key);
+            }
+        }
+        return new Result(persistableBundle, failedKeys);
+    }
+}