Notify DataUseTabModel of navigations and tab closures

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index 35ed57e46105cec561116b820744ba8a09afa885..6af76fa64daf1f36f0ece191a59e9762d699217a 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -114,6 +114,7 @@
 
 #if defined(OS_ANDROID)
 #include "base/android/build_info.h"
+#include "chrome/browser/android/data_usage/data_use_tab_model.h"
 #include "chrome/browser/android/data_usage/external_data_use_observer.h"
 #include "chrome/browser/android/net/external_estimate_provider_android.h"
 #include "components/data_usage/android/traffic_stats_amortizer.h"
@@ -636,6 +637,8 @@ void IOThread::Init() {
           data_use_aggregator(),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI)));
+  data_use_tab_model_ =
+      external_data_use_observer_->data_use_tab_model()->GetWeakPtr();
 #endif
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432