Support "shared" histograms between processes.

content/child/child_histogram_message_filter.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 "content/child/child_histogram_message_filter.h"
 
 #include <ctype.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 41 matching lines @@
   UploadAllHistograms(sequence_number);
 }
 
 void ChildHistogramMessageFilter::UploadAllHistograms(int sequence_number) {
   if (!histogram_delta_serialization_) {
     histogram_delta_serialization_.reset(
         new base::HistogramDeltaSerialization("ChildProcess"));
   }
 
   std::vector<std::string> deltas;
-  histogram_delta_serialization_->PrepareAndSerializeDeltas(&deltas);
+  histogram_delta_serialization_->PrepareAndSerializeDeltas(&deltas, false);
   sender_->Send(
       new ChildProcessHostMsg_ChildHistogramData(sequence_number, deltas));
 
 #ifndef NDEBUG
   static int count = 0;
   count++;
   LOCAL_HISTOGRAM_COUNTS("Histogram.ChildProcessHistogramSentCount", count);
 #endif
 }
 
 }  // namespace content