Add histograms for data usage

chrome/browser/android/data_usage/external_data_use_observer_bridge.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_DATA_USAGE_EXTERNAL_DATA_USE_OBSERVER_BRIDGE_H_
 #define CHROME_BROWSER_ANDROID_DATA_USAGE_EXTERNAL_DATA_USE_OBSERVER_BRIDGE_H_
 
 #include <jni.h>
 #include <stdint.h>
 
 #include <string>
 
 #include "base/android/jni_array.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "net/base/network_change_notifier.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 class Time;
+class TimeTicks;
 }
 
 namespace chrome {
 
 namespace android {
 
 class DataUseTabModel;
 class ExternalDataUseObserver;
 
 // ExternalDataUseObserverBridge creates and owns a Java listener object
@@ skipping 60 matching lines @@
   // reports are submitted to |j_external_data_use_observer_|.
   base::android::ScopedJavaGlobalRef<jobject> j_external_data_use_observer_;
 
   // |external_data_use_observer_| owns |this|. |external_data_use_observer_| is
   // notified of results from Java code by |this|.
   base::WeakPtr<ExternalDataUseObserver> external_data_use_observer_;
 
   // |data_use_tab_model_| is notified of the matching rules on UI thread.
   base::WeakPtr<DataUseTabModel> data_use_tab_model_;
 
+  // The construction time of |this|.
+  const base::TimeTicks construct_time_;
+
+  // True if matching rules are fetched for the first time.
+  bool is_first_matching_rule_fetch_;
+
   // |io_task_runner_| accesses ExternalDataUseObserver members on IO thread.
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalDataUseObserverBridge);
 };
 
 bool RegisterExternalDataUseObserver(JNIEnv* env);
 
 }  // namespace android
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_ANDROID_DATA_USAGE_EXTERNAL_DATA_USE_OBSERVER_BRIDGE_H_