Initial import of the Chrome Frame codebase. Integration in chrome.gyp coming...

chrome_frame/chrome_frame_histograms.h

Index: chrome_frame/chrome_frame_histograms.h
===================================================================
--- chrome_frame/chrome_frame_histograms.h	(revision 0)
+++ chrome_frame/chrome_frame_histograms.h	(revision 0)
@@ -0,0 +1,54 @@
+// Copyright (c) 2009 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.
+
+#ifndef CHROME_FRAME_HISTOGRAM_SNAPSHOTS_H_
+#define CHROME_FRAME_HISTOGRAM_SNAPSHOTS_H_
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/histogram.h"
+#include "base/process.h"
+#include "base/scoped_ptr.h"
+#include "base/task.h"
+
+// This class gathers histogram data in the host browser process and
+// serializes the data into a vector of strings to be uploaded to the
+// Chrome browser process. It records the histogram data which has been
+// logged and only uploads the delta with the next log.
+// TODO(iyengar)
+// This class does not contain any ChromeFrame specific stuff. It should
+// be moved to base.
+class ChromeFrameHistogramSnapshots {
+ public:
+  // Maintain a map of histogram names to the sample stats we've sent.
+  typedef std::map<std::string, Histogram::SampleSet> LoggedSampleMap;
+  typedef std::vector<std::string> HistogramPickledList;
+
+  ChromeFrameHistogramSnapshots();
+  ~ChromeFrameHistogramSnapshots() {}
+
+  // Extract snapshot data and return it to be sent off to the Chrome browser
+  // process.
+  // Return only a delta to what we have already sent.
+  HistogramPickledList GatherAllHistograms();
+
+ private:
+  void GatherHistogram(const Histogram& histogram,
+                       HistogramPickledList* histograms);
+
+  void GatherHistogramDelta(const Histogram& histogram,
+                            const Histogram::SampleSet& snapshot,
+                            HistogramPickledList* histograms);
+
+  // For histograms, record what we've already logged (as a sample for each
+  // histogram) so that we can send only the delta with the next log.
+  LoggedSampleMap logged_samples_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeFrameHistogramSnapshots);
+};
+
+#endif  // CHROME_RENDERER_HISTOGRAM_SNAPSHOTS_H_