Add a metrics extensions API....

chrome/browser/extensions/extension_metrics_apitest.cc

+// 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.
+
+#include <map>
+
+#include "base/histogram.h"
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/extensions/extension_apitest.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/notification_registrar.h"
+
+namespace {
+
+// The tests that are run by this extension are expected to record the following
+// user actions, with the specified counts.  If the tests in test.js are
+// modified, this array may need to be updated.
+struct RecordedUserAction {
+  const char* name;  // base name of metric without extension id.
+  int count;  // number of times the metric was recorded.
+} g_user_actions[] = {
+  {"test.ua.1", 1},
+  {"test.ua.2", 2},
+};
+
+// The tests that are run by this extension are expected to record the following
+// histograms.  If the tests in test.js are modified, this array may need to be
+// updated.
+struct RecordedHistogram {
+  const char* name;  // base name of metric without extension id.
+  Histogram::ClassType type;
+  int min;
+  int max;
+  size_t buckets;
+} g_histograms[] = {
+  {"test.h.1", Histogram::HISTOGRAM, 1, 100, 50},  // custom
+  {"test.h.2", Histogram::LINEAR_HISTOGRAM, 1, 200, 50},  // custom
+  {"test.h.3", Histogram::LINEAR_HISTOGRAM, 1, 101, 102},  // percentage
+  {"test.time", Histogram::HISTOGRAM, 1, 10000, 50},
+  {"test.medium.time", Histogram::HISTOGRAM, 1, 180000, 50},
+  {"test.long.time", Histogram::HISTOGRAM, 1, 3600000, 50},
+  {"test.count", Histogram::HISTOGRAM, 1, 1000000, 50},
+  {"test.medium.count", Histogram::HISTOGRAM, 1, 10000, 50},
+  {"test.small.count", Histogram::HISTOGRAM, 1, 100, 50},
+};
+
+// Build the full name of a metrics for the given extension.  Each metric
+// is made up of the unique name within the extension followed by the
+// extension's id.
+std::string BuildFullName(const std::string& name, const Extension* extension) {
+  std::string full_name(name);
+  full_name += extension->id();
+  return full_name;
+}
+
+// This class observes and collects user action notifications that are sent
+// by the tests, so that they can be examined afterwards for correctness.
+class UserActionObserver : public NotificationObserver {
+ public:
+  UserActionObserver();
+
+  void ValidateUserActions(const Extension* extension,
+                           const RecordedUserAction* recorded,
+                           int count);
+
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+ private:
+  typedef std::map<std::string, int> UserActionCountMap;
+
+  int num_metrics() const {
+    return count_map_.size();
+  }
+
+  int GetMetricCount(const std::string& name) const {
+    UserActionCountMap::const_iterator i = count_map_.find(name);
+    return i == count_map_.end() ? -1 : i->second;
+  }
+
+  NotificationRegistrar registrar_;
+  UserActionCountMap count_map_;
+};
+
+UserActionObserver::UserActionObserver() {
+  registrar_.Add(this, NotificationType::USER_ACTION,
+                 NotificationService::AllSources());
+}
+
+void UserActionObserver::Observe(NotificationType type,
+                                 const NotificationSource& source,
+                                 const NotificationDetails& details) {
+  const char* name = *Details<const char*>(details).ptr();
+  ++(count_map_[name]);
+}
+
+void UserActionObserver::ValidateUserActions(const Extension* extension,
+                                             const RecordedUserAction* recorded,
+                                             int count) {
+  EXPECT_EQ(count, num_metrics());
+
+  for (int i = 0; i < count; ++i) {
+    const RecordedUserAction& ua = recorded[i];
+    EXPECT_EQ(ua.count, GetMetricCount(BuildFullName(ua.name, extension)));
+  }
+}
+
+void ValidateHistograms(const Extension* extension,
+                        const RecordedHistogram* recorded,
+                        int count) {
+  StatisticsRecorder::Histograms histograms;
+  StatisticsRecorder::GetHistograms(&histograms);
+
+  // Code other than the tests tun here will record some histogram values, but
+  // we will ignore those. This function validates that all the histogram we
+  // expect to see are present in the list, and that their basic info is
+  // correct.
+  for (int i = 0; i < count; ++i) {
+    const RecordedHistogram& r = recorded[i];
+    std::string name(BuildFullName(r.name, extension));
+
+    size_t j = 0;
+    for (j = 0; j < histograms.size(); ++j) {
+      scoped_refptr<Histogram> histogram(histograms[j]);
+
+      if (name == histogram->histogram_name()) {
+        EXPECT_EQ(r.type, histogram->histogram_type());
+        EXPECT_EQ(r.min, histogram->declared_min());
+        EXPECT_EQ(r.max, histogram->declared_max());
+        EXPECT_EQ(r.buckets, histogram->bucket_count());
+        break;
+      }
+    }
+    EXPECT_LT(j, histograms.size());
+  }
+}
+
+}  // anonymous namespace
+
+IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Metrics) {
+  UserActionObserver observer;
+
+  ASSERT_TRUE(RunExtensionTest("metrics")) << message_;
+  Extension* extension = GetSingleLoadedExtension();
+  ASSERT_TRUE(extension);
+
+  observer.ValidateUserActions(extension,
+                               g_user_actions,
+                               arraysize(g_user_actions));
+  ValidateHistograms(extension, g_histograms, arraysize(g_histograms));
+}