Put BrowserMetrics with embedded profiles into subdir for auto-upload.

base/metrics/persistent_histogram_allocator.h

Index: base/metrics/persistent_histogram_allocator.h
diff --git a/base/metrics/persistent_histogram_allocator.h b/base/metrics/persistent_histogram_allocator.h
index 8a8d4cb32a9b829e5cc339f09991a9008f70dd1a..a6006c9361ad7ddc22691d4053750fa54b53f3cc 100644
--- a/base/metrics/persistent_histogram_allocator.h
+++ b/base/metrics/persistent_histogram_allocator.h
@@ -435,6 +435,16 @@ class BASE_EXPORT GlobalHistogramAllocator
                                  FilePath* out_active_path,
                                  FilePath* out_spare_path);
 
+  // As above but puts the base files in a different "upload" directory. This
+  // is useful when moving all completed files into a single directory for easy
+  // upload management.
+  static void ConstructFilePathsForUploadDir(const FilePath& active_dir,
+                                             const FilePath& upload_dir,
+                                             const std::string& name,

[Alexei Svitkine (slow), 2017/06/28 17:30:35]

StringPiece especially since you pass in kBrowserMetricsName which isn't a
std::string.

[bcwhite, 2017/06/28 18:52:08]

std::string takes a char* no problem.  Inside, though, all conditions lead to
the parameter needing to be a std::string so it's better to take it that way in
the parameter list and have it converted at most once, possibly never if the
caller already has it that way.

In the other ConstructFilePaths, the most common case doesn't need a std::string
so, combined with most callers having the name as a StringPiece, it's more
efficient to have the parameter being a StringPiece.

[Alexei Svitkine (slow), 2017/06/28 19:19:09]

Ah right, because you're converting via .as_string() later otherwise. Fair
enough. Made a small suggestion about those but otherwise sg.

+                                             FilePath* out_upload_path,
+                                             FilePath* out_active_path,
+                                             FilePath* out_spare_path);
+
   // Create a "spare" file that can later be made the "active" file. This
   // should be done on a background thread if possible.
   static bool CreateSpareFile(const FilePath& spare_path, size_t size);