Moving ShortcutInfo creation in InstallShortcutReceiver to background thread

> Creating shortcut info requires iconCache access

Bug: 21325319
Change-Id: I3317d8b6824aa05b836f3ed3626f169d4d34f783

src/com/android/launcher3/util/Provider.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016 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.launcher3.util;
+
+/**
+ * Utility class to allow lazy initialization of objects.
+ */
+public abstract class Provider<T> {
+
+    /**
+     * Initializes and returns the object. This may contain expensive operations not suitable
+     * to UI thread.
+     */
+    public abstract T get();
+
+    public static <T> Provider<T> of (final T value) {
+        return new Provider<T>() {
+            @Override
+            public T get() {
+                return value;
+            }
+        };
+    }
+}