Make base::Timer sequence-friendly.

content/browser/loader/upload_progress_tracker.h

Index: content/browser/loader/upload_progress_tracker.h
diff --git a/content/browser/loader/upload_progress_tracker.h b/content/browser/loader/upload_progress_tracker.h
index 6840f5a60bc174c5a01e547df2539b9878a74970..4f5e573c3f50a57db6fcd415dec46b5dc24cb449 100644
--- a/content/browser/loader/upload_progress_tracker.h
+++ b/content/browser/loader/upload_progress_tracker.h
@@ -10,8 +10,8 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/single_thread_task_runner.h"
-#include "base/threading/thread_task_runner_handle.h"
+#include "base/sequenced_task_runner.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "content/common/content_export.h"
@@ -41,13 +41,15 @@ class CONTENT_EXPORT UploadProgressTracker {
   UploadProgressTracker(const tracked_objects::Location& location,
                         UploadProgressReportCallback report_progress,
                         net::URLRequest* request,
-                        scoped_refptr<base::SingleThreadTaskRunner>
-                            task_runner = base::ThreadTaskRunnerHandle::Get());
+                        scoped_refptr<base::SequencedTaskRunner> task_runner =
+                            base::SequencedTaskRunnerHandle::Get());
   ~UploadProgressTracker();
 
   void OnAckReceived();
   void OnUploadCompleted();
 
+  static base::TimeDelta GetUploadProgressIntervalForTesting();
+
  private:
   // Overridden by tests to use a fake time and progress.
   virtual base::TimeTicks GetCurrentTime() const;