Consolidate serialization code in base::HistogramDeltasSerializer.

content/child/child_histogram_message_filter.h

Index: content/child/child_histogram_message_filter.h
diff --git a/content/child/child_histogram_message_filter.h b/content/child/child_histogram_message_filter.h
index 85d2e2097f180aec53117fa366b0688c6b6f2c7f..406f71467ab95812c2e9aa4fa9becf40aec52698 100644
--- a/content/child/child_histogram_message_filter.h
+++ b/content/child/child_histogram_message_filter.h
@@ -9,20 +9,16 @@
 #include <vector>
 
 #include "base/basictypes.h"
-#include "base/metrics/histogram_base.h"
-#include "base/metrics/histogram_flattener.h"
-#include "base/metrics/histogram_snapshot_manager.h"
 #include "ipc/ipc_channel_proxy.h"
 
 namespace base {
-class HistogramSamples;
+class HistogramDeltasSerializer;
 class MessageLoopProxy;
 }  // namespace base
 
 namespace content {
 
-class ChildHistogramMessageFilter : public base::HistogramFlattener,
-                                    public IPC::ChannelProxy::MessageFilter {
+class ChildHistogramMessageFilter : public IPC::ChannelProxy::MessageFilter {
  public:
   ChildHistogramMessageFilter();
 
@@ -33,15 +29,6 @@ class ChildHistogramMessageFilter : public base::HistogramFlattener,
 
   void SendHistograms(int sequence_number);
 
-  // HistogramFlattener interface (override) methods.
-  virtual void RecordDelta(const base::HistogramBase& histogram,
-                           const base::HistogramSamples& snapshot) OVERRIDE;
-  virtual void InconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) OVERRIDE;
-  virtual void UniqueInconsistencyDetected(
-      base::HistogramBase::Inconsistency problem) OVERRIDE;
-  virtual void InconsistencyDetectedInLoggedCount(int amount) OVERRIDE;
-
  private:
   typedef std::vector<std::string> HistogramPickledList;
 
@@ -58,11 +45,8 @@ class ChildHistogramMessageFilter : public base::HistogramFlattener,
 
   scoped_refptr<base::MessageLoopProxy> io_message_loop_;
 
-  // Collection of histograms to send to the browser.
-  HistogramPickledList pickled_histograms_;
-
-  // |histogram_snapshot_manager_| prepares histogram deltas for transmission.
-  base::HistogramSnapshotManager histogram_snapshot_manager_;
+  // Prepares histogram deltas for transmission.
+  scoped_ptr<base::HistogramDeltasSerializer> histogram_delta_serializer_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildHistogramMessageFilter);
 };