Downloads: replace BrowserThread::FILE with task scheduler.

content/browser/download/download_item_impl_unittest.cc

Index: content/browser/download/download_item_impl_unittest.cc
diff --git a/content/browser/download/download_item_impl_unittest.cc b/content/browser/download/download_item_impl_unittest.cc
index 1d10e52f4946c3627b33d0518e63e64d5e78071e..ee76123fcf964d1e8b1eee5e1c47c5b51bebe371 100644
--- a/content/browser/download/download_item_impl_unittest.cc
+++ b/content/browser/download/download_item_impl_unittest.cc
@@ -35,6 +35,7 @@
 #include "content/public/test/mock_download_item.h"
 #include "content/public/test/test_browser_context.h"
 #include "content/public/test/test_browser_thread_bundle.h"
+#include "content/public/test/test_utils.h"
 #include "content/public/test/web_contents_tester.h"
 #include "crypto/secure_hash.h"
 #include "net/http/http_response_headers.h"
@@ -393,7 +394,7 @@ class DownloadItemTest : public testing::Test {
     allocated_downloads_.erase(item);
   }
 
-  void RunAllPendingInMessageLoops() { base::RunLoop().RunUntilIdle(); }
+  void RunAllPendingInMessageLoops() { RunAllBlockingPoolTasksUntilIdle(); }

[gab, 2017/06/21 19:42:24]

inline below instead of having this indirection?

[Sigurður Ásgeirsson, 2017/06/22 14:50:09]

Done.

 
   MockDelegate* mock_delegate() {
     return &delegate_;
@@ -815,6 +816,8 @@ TEST_F(DownloadItemTest, AutomaticResumption_AttemptLimit) {
     mock_download_file_ref = mock_download_file.get();
     mock_request_handle = base::MakeUnique<NiceMock<MockRequestHandle>>();
 
+    EXPECT_CALL(*mock_download_file, Initialize(_, _, _, _))
+        .WillOnce(ScheduleCallbackWithParam(DOWNLOAD_INTERRUPT_REASON_NONE));

[gab, 2017/06/21 19:42:24]

Why is this changing?

[Sigurður Ásgeirsson, 2017/06/22 14:50:08]

As-is, the default mock setup fires the callback on-thread. The other places
where this a mock is used, it goes through a factory function that has this, but
that's apparently not applicable here.

... time passes ...

Actually the default behavior in the mock has other fallout, fixing at source.

     ON_CALL(*mock_download_file_ref, FullPath())
         .WillByDefault(ReturnRefOfCopy(base::FilePath()));