Add comments to HistogramFlatterner interface and rename a function

base/metrics/histogram_snapshot_manager.cc

 // Copyright (c) 2012 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.
 
 #include "base/metrics/histogram_snapshot_manager.h"
 
 #include "base/compiler_specific.h"
 #include "base/debug/alias.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/string_util.h"
@@ skipping 46 matching lines @@
   // a fair distance from the memory smasher, but we hope to correlate these
   // crashes with other events, such as plugins, or usage patterns, etc.
   if (Histogram::BUCKET_ORDER_ERROR & corruption) {
     // The checksum should have caught this, so crash separately if it didn't.
     CHECK_NE(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
     CHECK(false);  // Crash for the bucket order corruption.
   }
   // Checksum corruption might not have caused order corruption.
   CHECK_EQ(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
 
+  // Note, at this point corruption can only be COUNT_HIGH_ERROR or
+  // COUNT_LOW_ERROR and they never arise together, so we don't need to extract
+  // bits from corruption.
   if (corruption) {
     NOTREACHED();
-    histogram_flattener_->InconsistencyDetected(corruption);
+    histogram_flattener_->InconsistencyDetected(
+        static_cast<Histogram::Inconsistencies>(corruption));
     // Don't record corrupt data to metrics survices.
     if (NULL == inconsistencies_.get())
       inconsistencies_.reset(new ProblemMap);
     int old_corruption = (*inconsistencies_)[histogram_name];
     if (old_corruption == (corruption | old_corruption))
       return;  // We've already seen this corruption for this histogram.
     (*inconsistencies_)[histogram_name] |= corruption;
-    histogram_flattener_->UniqueInconsistencyDetected(corruption);
+    histogram_flattener_->UniqueInconsistencyDetected(
+        static_cast<Histogram::Inconsistencies>(corruption));
     return;
   }
 
   // Find the already recorded stats, or create an empty set. Remove from our
   // snapshot anything that we've already recorded.
   LoggedSampleMap::iterator it = logged_samples_.find(histogram_name);
   Histogram::SampleSet* already_logged;
   if (logged_samples_.end() == it) {
     // Add new entry
     already_logged = &logged_samples_[histogram.histogram_name()];
     // Complete initialization.
     already_logged->Resize(histogram.bucket_count());
   } else {
     already_logged = &(it->second);
     int64 discrepancy(already_logged->TotalCount() -
                       already_logged->redundant_count());
     if (discrepancy) {
       NOTREACHED();  // Already_logged has become corrupt.
       int problem = static_cast<int>(discrepancy);
       if (problem != discrepancy)
         problem = INT_MAX;
-      histogram_flattener_->SnapshotProblemResolved(problem);
+      histogram_flattener_->InconsistencyDetectedInLoggedCount(problem);
       // With no valid baseline, we'll act like we've recorded everything in our
       // snapshot.
       already_logged->Subtract(*already_logged);
       already_logged->Add(snapshot);
     }
     // Deduct any stats we've already logged from our snapshot.
     snapshot.Subtract(*already_logged);
   }
 
   // Snapshot now contains only a delta to what we've already_logged.
   if (snapshot.redundant_count() > 0) {
     histogram_flattener_->RecordDelta(histogram, snapshot);
     // Add new data into our running total.
     already_logged->Add(snapshot);
   }
 }
 }  // namespace base