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diff --git a/java/com/android/dialer/common/AsyncTaskExecutors.java b/java/com/android/dialer/common/AsyncTaskExecutors.java
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+++ b/java/com/android/dialer/common/AsyncTaskExecutors.java
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+/*
+ * Copyright (C) 2011 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.dialer.common;
+
+import android.os.AsyncTask;
+import android.support.annotation.MainThread;
+import java.util.concurrent.Executor;
+
+/**
+ * Factory methods for creating AsyncTaskExecutors.
+ *
+ * <p>All of the factory methods on this class check first to see if you have set a static {@link
+ * AsyncTaskExecutorFactory} set through the {@link #setFactoryForTest(AsyncTaskExecutorFactory)}
+ * method, and if so delegate to that instead, which is one way of injecting dependencies for
+ * testing classes whose construction cannot be controlled such as {@link android.app.Activity}.
+ */
+public final class AsyncTaskExecutors {
+
+  /**
+   * A single instance of the {@link AsyncTaskExecutorFactory}, to which we delegate if it is
+   * non-null, for injecting when testing.
+   */
+  private static AsyncTaskExecutorFactory mInjectedAsyncTaskExecutorFactory = null;
+
+  /**
+   * Creates an AsyncTaskExecutor that submits tasks to run with {@link AsyncTask#SERIAL_EXECUTOR}.
+   */
+  public static AsyncTaskExecutor createAsyncTaskExecutor() {
+    synchronized (AsyncTaskExecutors.class) {
+      if (mInjectedAsyncTaskExecutorFactory != null) {
+        return mInjectedAsyncTaskExecutorFactory.createAsyncTaskExeuctor();
+      }
+      return new SimpleAsyncTaskExecutor(AsyncTask.SERIAL_EXECUTOR);
+    }
+  }
+
+  /**
+   * Creates an AsyncTaskExecutor that submits tasks to run with {@link
+   * AsyncTask#THREAD_POOL_EXECUTOR}.
+   */
+  public static AsyncTaskExecutor createThreadPoolExecutor() {
+    synchronized (AsyncTaskExecutors.class) {
+      if (mInjectedAsyncTaskExecutorFactory != null) {
+        return mInjectedAsyncTaskExecutorFactory.createAsyncTaskExeuctor();
+      }
+      return new SimpleAsyncTaskExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+    }
+  }
+
+  public static void setFactoryForTest(AsyncTaskExecutorFactory factory) {
+    synchronized (AsyncTaskExecutors.class) {
+      mInjectedAsyncTaskExecutorFactory = factory;
+    }
+  }
+
+  /** Interface for creating AsyncTaskExecutor objects. */
+  public interface AsyncTaskExecutorFactory {
+
+    AsyncTaskExecutor createAsyncTaskExeuctor();
+  }
+
+  private static class SimpleAsyncTaskExecutor implements AsyncTaskExecutor {
+
+    private final Executor mExecutor;
+
+    public SimpleAsyncTaskExecutor(Executor executor) {
+      mExecutor = executor;
+    }
+
+    @Override
+    @MainThread
+    public <T> AsyncTask<T, ?, ?> submit(Object identifer, AsyncTask<T, ?, ?> task, T... params) {
+      Assert.isMainThread();
+      return task.executeOnExecutor(mExecutor, params);
+    }
+  }
+}