Fix flaky FileFlusherTest.DuplicateRequests

chrome/browser/chromeos/base/file_flusher.cc

Index: chrome/browser/chromeos/base/file_flusher.cc
diff --git a/chrome/browser/chromeos/base/file_flusher.cc b/chrome/browser/chromeos/base/file_flusher.cc
index 43e06b5875dd34e5c58c3c566196ba7c1a353dab..45d5d1375fee964cf59e69533b94c77b95b08283 100644
--- a/chrome/browser/chromeos/base/file_flusher.cc
+++ b/chrome/browser/chromeos/base/file_flusher.cc
@@ -4,6 +4,7 @@
 
 #include "chrome/browser/chromeos/base/file_flusher.h"
 
+#include <algorithm>
 #include <set>
 
 #include "base/bind.h"
@@ -68,6 +69,7 @@ class FileFlusher::Job {
 
   bool started_ = false;
   base::CancellationFlag cancel_flag_;
+  bool finish_scheduled_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(Job);
 };
@@ -143,6 +145,10 @@ bool FileFlusher::Job::ShouldExclude(const base::FilePath& path) const {
 }
 
 void FileFlusher::Job::ScheduleFinish() {
+  if (finish_scheduled_)
+    return;
+
+  finish_scheduled_ = true;
   content::BrowserThread::PostTask(
       content::BrowserThread::UI, FROM_HERE,
       base::Bind(&Job::FinishOnUIThread, base::Unretained(this)));
@@ -183,8 +189,19 @@ void FileFlusher::RequestFlush(const base::FilePath& path,
   ScheduleJob();
 }
 
+void FileFlusher::PauseForTest() {
+  DCHECK(std::none_of(jobs_.begin(), jobs_.end(),

[achuithb, 2016/09/15 18:36:56]

Wow, nice. It's like python.

+                      [](const Job* job) { return job->started(); }));
+  paused_for_test_ = true;
+}
+
+void FileFlusher::ResumeForTest() {
+  paused_for_test_ = false;
+  ScheduleJob();
+}
+
 void FileFlusher::ScheduleJob() {
-  if (jobs_.empty())
+  if (jobs_.empty() || paused_for_test_)
     return;
 
   auto* job = jobs_.front();