Updated negative-counts histogram for changes in logged/unlogged accounting.

base/metrics/persistent_sample_map.cc

Index: base/metrics/persistent_sample_map.cc
diff --git a/base/metrics/persistent_sample_map.cc b/base/metrics/persistent_sample_map.cc
index 743b64401cfa97741725ef2cf99aeeee6d2fe59e..af09f97702ea86f7371deb7b8a18e47fbeaca471 100644
--- a/base/metrics/persistent_sample_map.cc
+++ b/base/metrics/persistent_sample_map.cc
@@ -24,6 +24,9 @@ enum NegativeSampleReason {
   PERSISTENT_SPARSE_ADDED_NEGATIVE_COUNT,
   PERSISTENT_SPARSE_ADD_WENT_NEGATIVE,
   PERSISTENT_SPARSE_ADD_OVERFLOW,
+  PERSISTENT_SPARSE_ACCUMULATE_NEGATIVE_COUNT,
+  PERSISTENT_SPARSE_ACCUMULATE_WENT_NEGATIVE,
+  PERSISTENT_SPARSE_ACCUMULATE_OVERFLOW,
   MAX_NEGATIVE_SAMPLE_REASONS
 };
 
@@ -118,7 +121,26 @@ PersistentSampleMap::~PersistentSampleMap() {
 }
 
 void PersistentSampleMap::Accumulate(Sample value, Count count) {
+#if 0  // TODO(bcwhite) Re-enable efficient version after crbug.com/682680.
   *GetOrCreateSampleCountStorage(value) += count;
+#else
+  NegativeSampleReason reason = MAX_NEGATIVE_SAMPLE_REASONS;
+  Count* local_count_ptr = GetOrCreateSampleCountStorage(value);
+  if (count < 0) {
+    reason = PERSISTENT_SPARSE_ACCUMULATE_NEGATIVE_COUNT;
+    if (*local_count_ptr < -count)
+      reason = PERSISTENT_SPARSE_ACCUMULATE_WENT_NEGATIVE;
+    *local_count_ptr += count;
+  } else {
+    *local_count_ptr += count;
+    if (*local_count_ptr < 0)
+      reason = PERSISTENT_SPARSE_ACCUMULATE_OVERFLOW;
+  }
+  if (reason != MAX_NEGATIVE_SAMPLE_REASONS) {
+    UMA_HISTOGRAM_ENUMERATION("UMA.NegativeSamples.Reason", reason,
+                              MAX_NEGATIVE_SAMPLE_REASONS);
+  }
+#endif
   IncreaseSumAndCount(strict_cast<int64_t>(count) * value, count);
 }
 
@@ -195,48 +217,8 @@ bool PersistentSampleMap::AddSubtractImpl(SampleCountIterator* iter,
       continue;
     if (strict_cast<int64_t>(min) + 1 != max)
       return false;  // SparseHistogram only supports bucket with size 1.
-
-#if 0  // TODO(bcwhite) Re-enable efficient version after crbug.com/682680.
     *GetOrCreateSampleCountStorage(min) +=
         (op == HistogramSamples::ADD) ? count : -count;
-#else
-    NegativeSampleReason reason = MAX_NEGATIVE_SAMPLE_REASONS;
-    if (op == HistogramSamples::ADD) {
-      // Add should generally be adding only positive values.
-      Count* local_count_ptr = GetOrCreateSampleCountStorage(min);
-      if (count < 0) {
-        reason = PERSISTENT_SPARSE_ADDED_NEGATIVE_COUNT;
-        if (*local_count_ptr < -count) {
-          reason = PERSISTENT_SPARSE_ADD_WENT_NEGATIVE;
-          *local_count_ptr = 0;
-        }
-      } else {
-        *local_count_ptr += count;
-        if (*local_count_ptr < 0)
-          reason = PERSISTENT_SPARSE_ADD_OVERFLOW;
-      }
-    } else {
-      // Subtract is used only for determining deltas when reporting which
-      // means that it's in the "logged" iterator. It should have an active
-      // sample record and thus there is no need to try to create one.
-      Count* local_count_ptr = GetSampleCountStorage(min);
-      if (local_count_ptr == nullptr) {
-        reason = PERSISTENT_SPARSE_HAVE_LOGGED_BUT_NOT_SAMPLE;
-      } else {
-        if (*local_count_ptr < count) {
-          reason = PERSISTENT_SPARSE_SAMPLE_LESS_THAN_LOGGED;
-          *local_count_ptr = 0;
-        } else {
-          *local_count_ptr -= count;
-        }
-      }
-    }
-    if (reason != MAX_NEGATIVE_SAMPLE_REASONS) {
-      NOTREACHED();
-      UMA_HISTOGRAM_ENUMERATION("UMA.NegativeSamples.Reason", reason,
-                                MAX_NEGATIVE_SAMPLE_REASONS);
-    }
-#endif
   }
   return true;
 }