Support "shared" histograms between processes.

base/metrics/histogram_snapshot_manager.cc

Index: base/metrics/histogram_snapshot_manager.cc
diff --git a/base/metrics/histogram_snapshot_manager.cc b/base/metrics/histogram_snapshot_manager.cc
index 02f87f0105a9eee6f654fdc52d567d5a3dd56ffd..3d1c0d666a245050953d6899b9eb1423922f77ef 100644
--- a/base/metrics/histogram_snapshot_manager.cc
+++ b/base/metrics/histogram_snapshot_manager.cc
@@ -22,20 +22,6 @@ HistogramSnapshotManager::~HistogramSnapshotManager() {
   STLDeleteValues(&logged_samples_);
 }
 
-void HistogramSnapshotManager::PrepareDeltas(
-    HistogramBase::Flags flag_to_set,
-    HistogramBase::Flags required_flags) {
-  StatisticsRecorder::Histograms histograms;
-  StatisticsRecorder::GetHistograms(&histograms);
-  for (StatisticsRecorder::Histograms::const_iterator it = histograms.begin();
-       histograms.end() != it;
-       ++it) {
-    (*it)->SetFlags(flag_to_set);
-    if (((*it)->flags() & required_flags) == required_flags)
-      PrepareDelta(**it);
-  }
-}
-
 void HistogramSnapshotManager::PrepareDelta(const HistogramBase& histogram) {
   DCHECK(histogram_flattener_);