diff -r 000000000000 -r 6474c204b198 mobile/android/tests/background/junit3/src/helpers/FakeProfileTestCase.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/tests/background/junit3/src/helpers/FakeProfileTestCase.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,61 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+package org.mozilla.gecko.background.helpers;
+
+import java.io.File;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.test.ActivityInstrumentationTestCase2;
+import java.util.UUID;
+
+import org.mozilla.gecko.background.common.GlobalConstants;
+
+import org.mozilla.gecko.background.common.TestUtils;
+
+public abstract class FakeProfileTestCase extends ActivityInstrumentationTestCase2<Activity> {
+
+  protected Context context;
+  protected File fakeProfileDirectory;
+  private String sharedPrefsName;
+
+  public FakeProfileTestCase() {
+    super(Activity.class);
+  }
+
+  /**
+   * Returns the profile cache suffix. This is computed once for each test function (in setUp()).
+   * Note that the return value is not cached.
+   */
+  protected String getCacheSuffix() {
+    return this.getClass().getName() + "-" + System.currentTimeMillis();
+  }
+
+  @Override
+  protected void setUp() throws Exception {
+    super.setUp();
+    context = getInstrumentation().getTargetContext();
+    File cache = context.getCacheDir();
+    fakeProfileDirectory = new File(cache.getAbsolutePath() + getCacheSuffix());
+    if (fakeProfileDirectory.exists()) {
+      TestUtils.deleteDirectoryRecursively(fakeProfileDirectory);
+    }
+    if (!fakeProfileDirectory.mkdir()) {
+      throw new IllegalStateException("Could not create temporary directory.");
+    }
+    // Class name of the form: ActivityInstrumentationTestCase2$FakeProfileTestCase$extendingClass.
+    sharedPrefsName = this.getClass().getName() + "-" + UUID.randomUUID();
+  }
+
+  @Override
+  protected void tearDown() throws Exception {
+    TestUtils.deleteDirectoryRecursively(fakeProfileDirectory);
+    super.tearDown();
+  }
+
+  public SharedPreferences getSharedPreferences() {
+    return context.getSharedPreferences(sharedPrefsName, GlobalConstants.SHARED_PREFERENCES_MODE);
+  }
+}