Add histograms for data usage

chrome/browser/android/data_usage/external_data_use_observer_bridge.cc

 // Copyright 2015 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/android/data_usage/external_data_use_observer_bridge.h"
 
 #include <vector>
 
 #include "base/android/context_utils.h"
 #include "base/android/jni_string.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/data_usage/data_use_tab_model.h"
 #include "chrome/browser/android/data_usage/external_data_use_observer.h"
 #include "components/variations/variations_associated_data.h"
 #include "content/public/browser/browser_thread.h"
 #include "jni/ExternalDataUseObserver_jni.h"
 
 using base::android::ConvertUTF8ToJavaString;
 
 namespace {
 
 // Returns the package name of the control app from the field trial.
 const std::string GetControlAppPackageName() {
   return variations::GetVariationParamValue(
       chrome::android::ExternalDataUseObserver::
           kExternalDataUseObserverFieldTrial,
       "control_app_package_name");
 }
 
 }  // namespace
 
 namespace chrome {
 
 namespace android {
 
-ExternalDataUseObserverBridge::ExternalDataUseObserverBridge() {
+ExternalDataUseObserverBridge::ExternalDataUseObserverBridge()
+    : construct_time_(base::TimeTicks::Now()),
+      is_first_matching_rule_fetch_(true) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
 
   // Detach from IO thread since rest of ExternalDataUseObserverBridge lives on
   // the UI thread.
   thread_checker_.DetachFromThread();
 }
 
 ExternalDataUseObserverBridge::~ExternalDataUseObserverBridge() {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (j_external_data_use_observer_.is_null())
@@ skipping 39 matching lines @@
       env, j_external_data_use_observer_.obj());
 }
 
 void ExternalDataUseObserverBridge::FetchMatchingRulesDone(
     JNIEnv* env,
     const base::android::JavaParamRef<jobject>& obj,
     const base::android::JavaParamRef<jobjectArray>& app_package_name,
     const base::android::JavaParamRef<jobjectArray>& domain_path_regex,
     const base::android::JavaParamRef<jobjectArray>& label) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!construct_time_.is_null());
 
   // Convert to native objects.
   std::vector<std::string> app_package_name_native;
   std::vector<std::string> domain_path_regex_native;
   std::vector<std::string> label_native;
 
   if (app_package_name && domain_path_regex && label) {
     base::android::AppendJavaStringArrayToStringVector(
         env, app_package_name, &app_package_name_native);
     base::android::AppendJavaStringArrayToStringVector(
         env, domain_path_regex, &domain_path_regex_native);
     base::android::AppendJavaStringArrayToStringVector(env, label,
                                                        &label_native);
   }
 
   DCHECK_EQ(app_package_name_native.size(), domain_path_regex_native.size());
   DCHECK_EQ(app_package_name_native.size(), label_native.size());
 
   if (!data_use_tab_model_)
     return;
 
+  if (is_first_matching_rule_fetch_) {
+    is_first_matching_rule_fetch_ = false;
+    UMA_HISTOGRAM_TIMES("DataUsage.Perf.MatchingRuleFirstFetchDuration",
+                        base::TimeTicks::Now() - construct_time_);
+  }
+
   data_use_tab_model_->RegisterURLRegexes(
       app_package_name_native, domain_path_regex_native, label_native);
 }
 
 void ExternalDataUseObserverBridge::ReportDataUse(
     const std::string& label,
     net::NetworkChangeNotifier::ConnectionType connection_type,
     const std::string& mcc_mnc,
     const base::Time& start_time,
     const base::Time& end_time,
@@ skipping 34 matching lines @@
   data_use_tab_model_->OnControlAppInstalled();
 }
 
 bool RegisterExternalDataUseObserver(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace android
 
 }  // namespace chrome