Framework to ascribe all network data use to a source.

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 62fbb9f8e3e083c702462efa2d060d2588b74bfc..5d20997d0bc3fa7c76016fd622a183f04f3178ff 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -60,6 +60,10 @@ namespace data_usage {
 class DataUseAggregator;
 }
 
+namespace data_use_measurement {
+class ChromeDataUseAscriber;
+}
+
 namespace extensions {
 class EventRouterForwarder;
 }
@@ -128,6 +132,9 @@ class IOThread : public content::BrowserThreadDelegate {
     Globals();
     ~Globals();
 
+    // Ascribes all data use in Chrome to a source, such as page loads.
+    std::unique_ptr<data_use_measurement::ChromeDataUseAscriber>
+        data_use_ascriber;
     // Global aggregator of data use. It must outlive the
     // |system_network_delegate|.
     std::unique_ptr<data_usage::DataUseAggregator> data_use_aggregator;