Notify DataUseTabModel of navigations and tab closures

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 41c042fe8ac9fd2e3c84bae2927a22e1a268c699..a9f4c0d0bf403f0a9ec854b5972c2cdd282fe66f 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -38,6 +38,7 @@ class CommandLine;
 #if defined(OS_ANDROID)
 namespace chrome {
 namespace android {
+class DataUseTabModel;
 class ExternalDataUseObserver;
 }
 }
@@ -275,6 +276,12 @@ class IOThread : public content::BrowserThreadDelegate {
   // a result of a field trial or a command line flag.
   static bool ShouldEnableQuicForDataReductionProxy();
 
+#if defined(OS_ANDROID)
+  base::WeakPtr<chrome::android::DataUseTabModel> data_use_tab_model() const {
+    return data_use_tab_model_;
+  }
+#endif  // defined(OS_ANDROID)
+
  private:
   // Map from name to value for all parameters associate with a field trial.
   typedef std::map<std::string, std::string> VariationParameters;
@@ -537,6 +544,11 @@ class IOThread : public content::BrowserThreadDelegate {
 
   const base::TimeTicks creation_time_;
 
+#if defined(OS_ANDROID)
+  // WeakPtr to DataUseTabModel to be used on IO thread.

[sclittle, 2015/11/24 23:07:37]

Please be more specific - data_use_tab_model_ should only be dereferenced on the
IO thread, but should only be accessed on the UI thread after IOThread::Init ran
on the IO thread.

[tbansal1, 2015/11/25 20:55:16]

Obsolete.

+  base::WeakPtr<chrome::android::DataUseTabModel> data_use_tab_model_;
+#endif  // defined(OS_ANDROID)
+
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);