Introduce AndroidMetricsProvider class.

chrome/browser/metrics/android_metrics_provider.cc

Index: chrome/browser/metrics/android_metrics_provider.cc
===================================================================
--- chrome/browser/metrics/android_metrics_provider.cc	(revision 0)
+++ chrome/browser/metrics/android_metrics_provider.cc	(working copy)
@@ -0,0 +1,147 @@
+// Copyright 2014 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 "chrome/browser/metrics/android_metrics_provider.h"
+
+#include "base/metrics/histogram.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/scoped_user_pref_update.h"
+#include "base/values.h"
+#include "chrome/common/pref_names.h"
+
+namespace {
+
+// Increments a particular entry in the ListValue.
+void IncrementListValue(base::ListValue* counts, int index) {
+  int current_count = 0;
+  counts->GetInteger(index, &current_count);
+  counts->Set(index, new base::FundamentalValue(current_count + 1));
+}
+
+// Takes an int corresponding to a Type and returns the corresponding flag.
+int GetActivityFlag(int type_id) {
+  ActivityTypeIds::Type type = ActivityTypeIds::GetActivityType(type_id);
+  DCHECK_LT(type, ActivityTypeIds::ACTIVITY_MAX_VALUE);
+  return (1 << type);
+}
+
+}  // namespace
+
+AndroidMetricsProvider::AndroidMetricsProvider(PrefService* local_state)
+    : local_state_(local_state) {
+  LogStabilityToPrefs();
+}
+
+AndroidMetricsProvider::~AndroidMetricsProvider() {
+}
+
+
+void AndroidMetricsProvider::ProvideStabilityMetrics(
+    metrics::SystemProfileProto_Stability* stability_proto) {
+  ConvertStabilityPrefsToHistograms();
+}
+
+void AndroidMetricsProvider::LogStabilityToPrefs() {
+  // Track which Activities were launched by the user.
+  // A 'launch' is defined as starting the Activity at least once during a
+  // UMA session.  Multiple launches are counted only once since it is possible
+  // for users to hop between Activities (e.g. entering and leaving Settings).
+  const int launched =
+      local_state_->GetInteger(prefs::kStabilityLaunchedActivityFlags);
+  ListPrefUpdate update_launches(local_state_,
+                                 prefs::kStabilityLaunchedActivityCounts);
+  base::ListValue* launch_counts = update_launches.Get();
+  for (int activity_type = ActivityTypeIds::ACTIVITY_NONE;
+       activity_type < ActivityTypeIds::ACTIVITY_MAX_VALUE;
+       ++activity_type) {
+    if (launched & GetActivityFlag(activity_type))
+      IncrementListValue(launch_counts, activity_type);
+  }
+  local_state_->SetInteger(prefs::kStabilityLaunchedActivityFlags, 0);
+
+  // Track any Activities that were in the foreground when Chrome died.
+  // These Activities failed to be recorded as leaving the foreground, so Chrome
+  // couldn't have ended the UMA session cleanly.  Record them as crashing.
+  const int foreground =
+      local_state_->GetInteger(prefs::kStabilityForegroundActivityType);
+  if (foreground != ActivityTypeIds::ACTIVITY_NONE) {
+    ListPrefUpdate update_crashes(local_state_,
+                                  prefs::kStabilityCrashedActivityCounts);
+    base::ListValue* crash_counts = update_crashes.Get();
+    IncrementListValue(crash_counts, foreground);
+    local_state_->SetInteger(prefs::kStabilityForegroundActivityType,
+                             ActivityTypeIds::ACTIVITY_NONE);
+  }
+
+  local_state_->CommitPendingWrite();
+}
+
+void AndroidMetricsProvider::ConvertStabilityPrefsToHistograms() {
+  ListPrefUpdate launch_updater(local_state_,
+                                prefs::kStabilityLaunchedActivityCounts);
+  ListPrefUpdate crash_updater(local_state_,
+                               prefs::kStabilityCrashedActivityCounts);
+
+  base::ListValue* launch_counts = launch_updater.Get();
+  base::ListValue* crash_counts = crash_updater.Get();
+
+  for (int activity_type = ActivityTypeIds::ACTIVITY_NONE;
+       activity_type < ActivityTypeIds::ACTIVITY_MAX_VALUE;
+       ++activity_type) {
+    int launch_count = 0;
+    int crash_count = 0;
+
+    launch_counts->GetInteger(activity_type, &launch_count);
+    crash_counts->GetInteger(activity_type, &crash_count);
+
+    for (int count = 0; count < launch_count; ++count) {
+      UMA_STABILITY_HISTOGRAM_ENUMERATION(
+          "Chrome.Android.Activity.LaunchCounts",
+          activity_type,
+          ActivityTypeIds::ACTIVITY_MAX_VALUE);
+    }
+
+    for (int count = 0; count < crash_count; ++count) {
+      UMA_STABILITY_HISTOGRAM_ENUMERATION("Chrome.Android.Activity.CrashCounts",
+                                          activity_type,
+                                          ActivityTypeIds::ACTIVITY_MAX_VALUE);
+    }
+  }
+
+  launch_counts->Clear();
+  crash_counts->Clear();
+}
+
+void AndroidMetricsProvider::OnForegroundActivityChanged(
+    ActivityTypeIds::Type type) {
+  DCHECK_LT(type, ActivityTypeIds::ACTIVITY_MAX_VALUE);
+
+  if (type == local_state_->GetInteger(prefs::kStabilityForegroundActivityType))
+    return;
+
+  // Record that the Activity is now in the foreground.
+  local_state_->SetInteger(prefs::kStabilityForegroundActivityType, type);
+
+  // Record that the Activity was launched this sesaion.
+  // The pref stores a set of flags ORed together, where each set flag
+  // corresponds to a launched Activity type.
+  int launched =
+      local_state_->GetInteger(prefs::kStabilityLaunchedActivityFlags);
+  if (type != ActivityTypeIds::ACTIVITY_NONE) {
+    launched |= GetActivityFlag(type);
+    local_state_->SetInteger(prefs::kStabilityLaunchedActivityFlags, launched);
+  }
+
+  local_state_->CommitPendingWrite();
+}
+
+// static
+void AndroidMetricsProvider::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterIntegerPref(prefs::kStabilityForegroundActivityType,
+                                ActivityTypeIds::ACTIVITY_NONE);
+  registry->RegisterIntegerPref(prefs::kStabilityLaunchedActivityFlags, 0);
+  registry->RegisterListPref(prefs::kStabilityLaunchedActivityCounts);
+  registry->RegisterListPref(prefs::kStabilityCrashedActivityCounts);
+}