Set file tokens for NaCl main nexe if available to enable validation caching.

chrome/test/base/uma_histogram_helper.h

Index: chrome/test/base/uma_histogram_helper.h
diff --git a/chrome/test/base/uma_histogram_helper.h b/chrome/test/base/uma_histogram_helper.h
index b04178ce21b57b2f088e4b32843aee0e4e549170..76e841fcfd3651266eb709273d8a9b20d44ff400 100644
--- a/chrome/test/base/uma_histogram_helper.h
+++ b/chrome/test/base/uma_histogram_helper.h
@@ -26,6 +26,12 @@ class UMAHistogramHelper {
                           base::HistogramBase::Sample sample,
                           base::HistogramBase::Count expected_count);
 
+  // We know the exact number of samples in a bucket, but other buckets may
+  // have samples as well.
+  void ExpectBucketCount(const std::string& name,
+                          base::HistogramBase::Sample sample,
+                          base::HistogramBase::Count expected_count);
+
   // We don't know the values of the samples, but we know how many there are.
   void ExpectTotalCount(const std::string& name,
                         base::HistogramBase::Count count);