Add Sparse Histogram Support to metricsPrivate

chrome/browser/extensions/api/metrics_private/metrics_private_api.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_METRICS_PRIVATE_METRICS_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_METRICS_PRIVATE_METRICS_PRIVATE_API_H_
 
 #include <string>
 
 #include "base/metrics/histogram.h"
@@ skipping 65 matching lines @@
   DECLARE_EXTENSION_FUNCTION("metricsPrivate.recordValue",
                              METRICSPRIVATE_RECORDVALUE)
 
  protected:
   virtual ~MetricsPrivateRecordValueFunction() {}
 
   // ExtensionFunction:
   virtual bool RunImpl() OVERRIDE;
 };
 
+class MetricsPrivateRecordSparseValueFunction
+    : public MetricsHistogramHelperFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("metricsPrivate.recordSparseValue",
+                             METRICSPRIVATE_RECORDSPARSEVALUE)
+
+ protected:
+  virtual ~MetricsPrivateRecordSparseValueFunction() {}
+
+  // ExtensionFunction:
+  virtual bool RunImpl() OVERRIDE;
+};
+
 class MetricsPrivateRecordPercentageFunction
     : public MetricsHistogramHelperFunction {
  public:
   DECLARE_EXTENSION_FUNCTION("metricsPrivate.recordPercentage",
                              METRICSPRIVATE_RECORDPERCENTAGE)
 
  protected:
   virtual ~MetricsPrivateRecordPercentageFunction() {}
 
   // ExtensionFunction:
@@ skipping 73 matching lines @@
  protected:
   virtual ~MetricsPrivateRecordLongTimeFunction() {}
 
   // ExtensionFunction:
   virtual bool RunImpl() OVERRIDE;
 };
 
 } // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_METRICS_PRIVATE_METRICS_PRIVATE_API_H_