Fix flaky FileFlusherTest.DuplicateRequests

chrome/browser/chromeos/base/file_flusher_unittest.cc

 // Copyright 2016 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.
 
 #include "chrome/browser/chromeos/base/file_flusher.h"
 
 #include <map>
 #include <memory>
 
 #include "base/bind.h"
@@ skipping 118 matching lines @@
   EXPECT_EQ(0, GetFlushCount("dir1/file1"));
   EXPECT_EQ(0, GetFlushCount("dir1/file2"));
   EXPECT_EQ(1, GetFlushCount("dir1/file3"));
 
   EXPECT_EQ(0, GetFlushCount("dir1/Bad file"));
 }
 
 TEST_F(FileFlusherTest, DuplicateRequests) {
   std::unique_ptr<FileFlusher> flusher(CreateFileFlusher());
   base::RunLoop run_loop;
+  flusher->PauseForTest();
   flusher->RequestFlush(GetTestFilePath("dir1"), std::vector<base::FilePath>(),
                         base::Closure());
   flusher->RequestFlush(GetTestFilePath("dir1"), std::vector<base::FilePath>(),
                         run_loop.QuitClosure());
+  flusher->ResumeForTest();
   run_loop.Run();
 
   EXPECT_EQ(1, GetFlushCount("dir1/file1"));
   EXPECT_EQ(1, GetFlushCount("dir1/file2"));
   EXPECT_EQ(1, GetFlushCount("dir1/file3"));
 }
 
 }  // namespace chromeos