Batch data use objects in ExternalDataUseObserver

chrome/browser/android/data_usage/external_data_use_observer.h

Index: chrome/browser/android/data_usage/external_data_use_observer.h
diff --git a/chrome/browser/android/data_usage/external_data_use_observer.h b/chrome/browser/android/data_usage/external_data_use_observer.h
index 7ec350fe4e9e8364e556dd745c6dc1deebb30235..97d8f95554d1d9b18fb01ef57fc4406a0841605e 100644
--- a/chrome/browser/android/data_usage/external_data_use_observer.h
+++ b/chrome/browser/android/data_usage/external_data_use_observer.h
@@ -5,6 +5,9 @@
 #ifndef CHROME_BROWSER_ANDROID_DATA_USAGE_EXTERNAL_DATA_USE_OBSERVER_H_
 #define CHROME_BROWSER_ANDROID_DATA_USAGE_EXTERNAL_DATA_USE_OBSERVER_H_
 
+#include <deque>
+#include <memory>
+
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ -91,6 +94,9 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // data_usage::DataUseAggregator::Observer implementation:
   void OnDataUse(const data_usage::DataUse& data_use) override;
 
+  // Called when a batch of data use objects are added to |data_use_list_|.
+  void OnDataUseBatchComplete();
+
   // Aggregator that sends data use observations to |this|.
   data_usage::DataUseAggregator* data_use_aggregator_;
 
@@ -107,6 +113,14 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // created on IO thread but afterwards, should only be accessed on UI thread.
   ExternalDataUseReporter* external_data_use_reporter_;
 
+  // Batches the data use objects reported by DataUseAggregator. This will be
+  // created when data use batching starts and released when the batching ends.
+  // This will be null if there is no ongoing batching of data use objects.
+  std::unique_ptr<std::deque<const data_usage::DataUse>> data_use_list_;
+
+  // |io_task_runner_| is used to call methods on IO thread.
+  scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
+
   // |ui_task_runner_| is used to call methods on UI thread.
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;