Persist setup metrics and have Chrome report them during UMA upload.

base/metrics/histogram_persistence.h

 // Copyright (c) 2015 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 "base/base_export.h"
 #include "base/feature_list.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 17 matching lines @@
 // be pointers to data held in that space.
 BASE_EXPORT void SetPersistentHistogramMemoryAllocator(
     PersistentMemoryAllocator* allocator);
 BASE_EXPORT PersistentMemoryAllocator* GetPersistentHistogramMemoryAllocator();
 
 // This access to the persistent allocator is only for testing; it extracts
 // the current allocator completely. This allows easy creation of histograms
 // within persistent memory segments which can then be extracted and used
 // in other ways.
 BASE_EXPORT PersistentMemoryAllocator*
-ReleasePersistentHistogramMemoryAllocator();
+ReleasePersistentHistogramMemoryAllocatorForTesting();
 
 // Recreate a Histogram from data held in persistent memory. Though this
 // object will be local to the current process, the sample data will be
 // shared with all other threads referencing it. This method takes a |ref|
 // to the top- level histogram data and the |allocator| on which it is found.
 // This method will return nullptr if any problem is detected with the data.
 // The |allocator| may or may not be the same as the PersistentMemoryAllocator
 // set for general use so that this method can be used to extract Histograms
 // from persistent memory segments other than the default place that this
 // process is creating its own histograms. The caller must take ownership of
@@ skipping 31 matching lines @@
 // possible for other processes to create histograms in the attached memory
 // segment; this adds those to the internal list of known histograms to
 // avoid creating duplicates that would have to merged during reporting.
 // Every call to this method resumes from the last entry it saw so it costs
 // nothing if nothing new has been added.
 void ImportPersistentHistograms();
 
 }  // namespace base
 
 #endif  // BASE_METRICS_HISTOGRAM_PERSISTENCE_H_