Bug 1256366 - Remove linear and exponential stats collection from histogram.cc. r=gfritzsche

--HG--
extra : rebase_source : 0432153cd79b63c1618056988ff354d5a9b1f4ea

ipc/chromium/src/base/histogram.cc

@@ -567,7 +567,7 @@ const std::string Histogram::GetAsciiBucketRange(size_t i) const {
 
 // Update histogram data with new sample.
 void Histogram::Accumulate(Sample value, Count count, size_t index) {
-  sample_.AccumulateWithLinearStats(value, count, index);
+  sample_.Accumulate(value, count, index);
 }
 
 void Histogram::SetBucketRange(size_t i, Sample value) {
@@ -720,9 +720,6 @@ void Histogram::WriteAsciiBucketGraph(double current_size, double max_size,
 Histogram::SampleSet::SampleSet()
     : counts_(),
       sum_(0),
-      sum_squares_(0),
-      log_sum_(0),
-      log_sum_squares_(0),
       redundant_count_(0),
       mutex_("Histogram::SampleSet::SampleSet") {
 }
@@ -747,12 +744,11 @@ void Histogram::SampleSet::Accumulate(const OffTheBooksMutexAutoLock& ev,
   DCHECK_GE(redundant_count_, 0);
 }
 
-void Histogram::SampleSet::AccumulateWithLinearStats(Sample value,
-                                                     Count count,
-                                                     size_t index) {
+void Histogram::SampleSet::Accumulate(Sample value,
+                                      Count count,
+                                      size_t index) {
   OffTheBooksMutexAutoLock locker(mutex_);
   Accumulate(locker, value, count, index);
-  sum_squares_ += static_cast<int64_t>(count) * value * value;
 }
 
 Count Histogram::SampleSet::TotalCount(const OffTheBooksMutexAutoLock& ev)
@@ -770,9 +766,6 @@ void Histogram::SampleSet::Add(const SampleSet& other) {
   OffTheBooksMutexAutoLock locker(mutex_);
   DCHECK_EQ(counts_.size(), other.counts_.size());
   sum_ += other.sum_;
-  sum_squares_ += other.sum_squares_;
-  log_sum_ += other.log_sum_;
-  log_sum_squares_ += other.log_sum_squares_;
   redundant_count_ += other.redundant_count_;
   for (size_t index = 0; index < counts_.size(); ++index)
     counts_[index] += other.counts_[index];
@@ -868,7 +861,7 @@ Histogram::ClassType LinearHistogram::histogram_type() const {
 }
 
 void LinearHistogram::Accumulate(Sample value, Count count, size_t index) {
-  sample_.AccumulateWithLinearStats(value, count, index);
+  sample_.Accumulate(value, count, index);
 }
 
 void LinearHistogram::SetRangeDescriptions(

ipc/chromium/src/base/histogram.h

@@ -353,7 +353,7 @@ class Histogram {
     void Resize(const Histogram& histogram);
 
     // Accessor for histogram to make routine additions.
-    void AccumulateWithLinearStats(Sample value, Count count, size_t index);
+    void Accumulate(Sample value, Count count, size_t index);
 
     // Arithmetic manipulation of corresponding elements of the set.
     void Add(const SampleSet& other);
@@ -375,15 +375,6 @@ class Histogram {
     int64_t sum(const OffTheBooksMutexAutoLock& ev) const {
        return sum_;
     }
-    uint64_t sum_squares(const OffTheBooksMutexAutoLock& ev) const {
-       return sum_squares_;
-    }
-    double log_sum(const OffTheBooksMutexAutoLock& ev) const {
-       return log_sum_;
-    }
-    double log_sum_squares(const OffTheBooksMutexAutoLock& ev) const {
-       return log_sum_squares_;
-    }
     int64_t redundant_count(const OffTheBooksMutexAutoLock& ev) const {
        return redundant_count_;
     }
@@ -396,9 +387,6 @@ class Histogram {
     const SampleSet& operator=(const SampleSet& other) {
        counts_          = other.counts_;
        sum_             = other.sum_;
-       sum_squares_     = other.sum_squares_;
-       log_sum_         = other.log_sum_;
-       log_sum_squares_ = other.log_sum_squares_;
        redundant_count_ = other.redundant_count_;
        return *this;
     }
@@ -415,13 +403,6 @@ class Histogram {
     // Save simple stats locally.  Note that this MIGHT get done in base class
     // without shared memory at some point.
     int64_t sum_;         // sum of samples.
-    uint64_t sum_squares_; // sum of squares of samples.
-
-    // These fields may or may not be updated at the discretion of the
-    // histogram.  We use the natural log and compute ln(sample+1) so that
-    // zeros are handled sanely.
-    double log_sum_;      // sum of logs of samples.
-    double log_sum_squares_; // sum of squares of logs of samples
 
     // To help identify memory corruption, we reduntantly save the number of
     // samples we've accumulated into all of our buckets.  We can compare this