Disable FileUtilTest.ReadFileToStringWithNamedPipe for being flaky

The test is timing out on Android. More details in the bug.

TBR=kylechar@chromium.org

Bug: 902674
Change-Id: I080e46a5b15d1e4742793ce3ca4f992147a8b90a
Reviewed-on: https://chromium-review.googlesource.com/c/1322830
Reviewed-by: Rayan Kanso <rayankans@chromium.org>
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606012}

base/files/file_util_unittest.cc

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