Submit buffered data use reports when Chromium is backgrounded

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 76584900fd8017e1f10041962c8ca5278535fe0d..a2521bedb426401dc4283849b787f95908c4561f 100644
--- a/chrome/browser/android/data_usage/external_data_use_observer.h
+++ b/chrome/browser/android/data_usage/external_data_use_observer.h
@@ -21,6 +21,10 @@
 #include "components/data_usage/core/data_use_aggregator.h"
 #include "net/base/network_change_notifier.h"
 
+#if defined(OS_ANDROID)
+#include "base/android/application_status_listener.h"
+#endif
+
 namespace base {
 class SingleThreadTaskRunner;
 }
@@ -77,6 +81,12 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // successfully submitted to the external data use observer by Java.
   void OnReportDataUseDone(bool success);
 
+#if defined(OS_ANDROID)
+  // Called whenever the application transitions from foreground to background
+  // and vice versa.
+  void OnApplicationStateChange(base::android::ApplicationState new_state);

[tbansal1, 2015/12/21 21:03:24]

Does this method need to be public?

[Raj, 2015/12/29 23:17:35]

Done.

+#endif
+
   // Called by DataUseMatcher. |should_register| is true if |this| should
   // register as a data use observer.
   void ShouldRegisterAsDataUseObserver(bool should_register);
@@ -190,8 +200,10 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // |buffered_data_reports_|. Since an unordered map is used to buffer the
   // reports, the order of reports may change. The reports are buffered in an
   // arbitrary order and there are no guarantees that the next report to be
-  // submitted is the oldest one buffered.
-  void SubmitBufferedDataUseReport();
+  // submitted is the oldest one buffered. |immediate| indicates whether to
+  // submit the report immediately or to wait until |data_use_report_min_bytes_|
+  // unreported bytes are buffered.
+  void SubmitBufferedDataUseReport(bool immediate);
 
   // Aggregator that sends data use observations to |this|.
   data_usage::DataUseAggregator* data_use_aggregator_;
@@ -242,6 +254,12 @@ class ExternalDataUseObserver : public data_usage::DataUseAggregator::Observer {
   // duration, it is considered as timed out.
   const base::TimeDelta data_report_submit_timeout_;
 
+#if defined(OS_ANDROID)
+  // ApplicationStatusListener used to listen when Chromium gets backgrounded
+  // and submit buffered data use reports.
+  scoped_ptr<base::android::ApplicationStatusListener> app_state_listener_;
+#endif
+
   // True if |this| is currently registered as a data use observer.
   bool registered_as_data_use_observer_;