Fix flaky multiprocess FileUtilTest test on Android

FileUtilTest.ReadFileToStringWithNamedPipe has been flaking since
http://crrev.com/c/1298024 landed.

I believe FileUtilTest.ReadFileToStringWithNamedPipe was failing because
it creates 6 processes one after another. We only have 5 test processes,
so in some cases one was not available to be reused for the 6th process.
Doubling the number of test processes to 10 should fix this.

Bug: 902674
Change-Id: I7e6204b5fda28155de8d501ccb5e0e5d2754849e
Reviewed-on: https://chromium-review.googlesource.com/c/1338393Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Tommy Nyquist <nyquist@chromium.org>
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608827}

base/files/file_util_unittest.cc

@@ -2913,8 +2913,7 @@ MULTIPROCESS_TEST_MAIN(MoreThanBufferSizeChildMain) {
   return 0;
 }
 
-// Times out on Android. http://crbug.com/902674.
-TEST_F(FileUtilTest, DISABLED_ReadFileToStringWithNamedPipe) {
+TEST_F(FileUtilTest, ReadFileToStringWithNamedPipe) {
   FilePath pipe_path =
       temp_dir_.GetPath().Append(FILE_PATH_LITERAL("test_pipe"));
   ASSERT_EQ(0, mkfifo(pipe_path.value().c_str(), 0600));

base/test/BUILD.gn

@@ -438,6 +438,11 @@ if (is_android) {
       "android/java/src/org/chromium/base/MultiprocessTestClientService2.java",
       "android/java/src/org/chromium/base/MultiprocessTestClientService3.java",
       "android/java/src/org/chromium/base/MultiprocessTestClientService4.java",
+      "android/java/src/org/chromium/base/MultiprocessTestClientService5.java",
+      "android/java/src/org/chromium/base/MultiprocessTestClientService6.java",
+      "android/java/src/org/chromium/base/MultiprocessTestClientService7.java",
+      "android/java/src/org/chromium/base/MultiprocessTestClientService8.java",
+      "android/java/src/org/chromium/base/MultiprocessTestClientService9.java",
       "android/java/src/org/chromium/base/MultiprocessTestClientServiceDelegate.java",
     ]
   }

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService5.java

+// Copyright 2018 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.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService5 extends MultiprocessTestClientService {}

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService6.java

+// Copyright 2018 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.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService6 extends MultiprocessTestClientService {}

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService7.java

+// Copyright 2018 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.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService7 extends MultiprocessTestClientService {}

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService8.java

+// Copyright 2018 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.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService8 extends MultiprocessTestClientService {}

base/test/android/java/src/org/chromium/base/MultiprocessTestClientService9.java

+// Copyright 2018 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.base;
+
+/**
+ * A subclass used only to differentiate different test client service process instances.
+ */
+public class MultiprocessTestClientService9 extends MultiprocessTestClientService {}

testing/android/native_test/java/AndroidManifest.xml.jinja2

@@ -52,7 +52,7 @@ found in the LICENSE file.
 
         <!-- If you change the number below, make sure to add/remove actual service classes
              org/chromium/base/MultiprocessTestClientService*.java -->
-        {% set num_test_client_services = 5 %}
+        {% set num_test_client_services = 10 %}
         <meta-data android:name="org.chromium.native_test.NUM_TEST_CLIENT_SERVICES"
                    android:value="{{ num_test_client_services }}"/>
         {% for i in range(num_test_client_services) %}