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 1f0d5f968cac8c98f32c1e198fc9a3b21f898815..a854aa5565c85576499534de7708ee4d281f9d66 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -116,6 +116,7 @@
 
 #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"
@@ -639,6 +640,8 @@ void IOThread::Init() {
           globals_->data_use_aggregator.get(),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO),
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI)));
+  data_use_tab_model_ =
+      globals_->external_data_use_observer->GetDataUseTabModel()->GetWeakPtr();
 #endif
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432