Add histogram to track number of .nexe launches, normalized against opening new tabs.

BUG=914 (http://code.google.com/p/nativeclient/issues/detail?id=914)
TEST=none
  Relied on trybots and manually checking "about:histograms"

Review URL: http://codereview.chromium.org/4065005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64261 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 52 insertions, 0 deletions

diff --git a/base/metrics/nacl_histogram.cc b/base/metrics/nacl_histogram.cc
new file mode 100644
index 0000000..c89e646
--- /dev/null
+++ b/base/metrics/nacl_histogram.cc
@@ -0,0 +1,23 @@
+// Copyright (c) 2010 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.
+
+// nacl_histogram provides an enum and defines a macro that uses definitions
+// from histogram.h. Note that a histogram is an object that aggregates
+// statistics, and can summarize them in various forms, including ASCII
+// graphical, HTML, and numerically.
+// nacl_histogram information is used to compare how many times a native
+// client module has been loaded, compared to the number of chrome starts
+// and number of new tabs created.
+
+
+#include "base/metrics/histogram.h"
+#include "base/metrics/nacl_histogram.h"
+
+// To log histogram data about NaCl.Startups, call this function with
+// a NaClHistogramValue passed in as |hvalue|
+void UmaNaclHistogramEnumeration(NaClHistogramValue histogram_value) {
+  UMA_HISTOGRAM_ENUMERATION("NaCl.Startups", histogram_value,
+    NACL_MAX_HISTOGRAM);
+}
+
diff --git a/base/metrics/nacl_histogram.h b/base/metrics/nacl_histogram.h
new file mode 100644
index 0000000..479b571
--- /dev/null
+++ b/base/metrics/nacl_histogram.h
@@ -0,0 +1,29 @@
+// Copyright (c) 2010 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.
+
+// nacl_histogram provides an enum and defines a macro that uses definitions
+// from histogram.h. Note that a histogram is an object that aggregates
+// statistics, and can summarize them in various forms, including ASCII
+// graphical, HTML, and numerically.
+// nacl_histogram information is used to compare how many times a native
+// client module has been loaded, compared to the number of chrome starts
+// and number of new tabs created.
+
+#ifndef BASE_METRICS_NACL_HISTOGRAM_H_
+#define BASE_METRICS_NACL_HISTOGRAM_H_
+#pragma once
+
+enum NaClHistogramValue {
+  FIRST_TAB_NACL_BASELINE,   // First tab created - a baseline for NaCl starts.
+  NEW_TAB_NACL_BASELINE,     // New tab created -- a baseline for NaCl starts.
+  NACL_STARTED,              // NaCl process started
+  NACL_MAX_HISTOGRAM         // DO NOT USE -- used by histogram for max bound.
+};
+
+// To log histogram data about NaCl.Startups, call this macro with
+// a NaClHistogramValue passed in as |histogram_value|
+void UmaNaclHistogramEnumeration(NaClHistogramValue histogram_value);
+
+#endif  // BASE_METRICS_NACL_HISTOGRAM_H_
+