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

base/metrics/persistent_histogram_allocator.h

 // 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.
 
 #ifndef BASE_METRICS_HISTOGRAM_PERSISTENCE_H_
 #define BASE_METRICS_HISTOGRAM_PERSISTENCE_H_
 
 #include <map>
 #include <memory>
 
@@ skipping 417 matching lines @@
   // The spare path is a file that can be pre-created and moved to be active
   // without any startup penalty that comes from constructing the file. |name|
   // will be used as the basename of the file inside |dir|. |out_base_path|,
   // |out_active_path|, or |out_spare_path| may be null if not needed.
   static void ConstructFilePaths(const FilePath& dir,
                                  StringPiece name,
                                  FilePath* out_base_path,
                                  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);
 
   // Same as above but uses standard names. |name| is the name of the allocator
   // and is also used to create the correct filename.
   static bool CreateSpareFileInDir(const FilePath& dir_path,
                                    size_t size,
                                    StringPiece name);
 #endif
@@ skipping 62 matching lines @@
 
   // The location to which the data should be persisted.
   FilePath persistent_location_;
 
   DISALLOW_COPY_AND_ASSIGN(GlobalHistogramAllocator);
 };
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_PERSISTENCE_H_