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 f57bc395a0eb16e6b0e6966ac96c5461a152ea8d..79478046277be138a1ec696f440f089248864866 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -39,6 +39,7 @@ class CommandLine;
 #if defined(OS_ANDROID)
 namespace chrome {
 namespace android {
+class DataUseTabModel;
 class ExternalDataUseObserver;
 }
 }
@@ -267,9 +268,13 @@ class IOThread : public content::BrowserThreadDelegate {
   static bool ShouldEnableQuicForDataReductionProxy();
 
 #if defined(OS_ANDROID)
-chrome::android::ExternalDataUseObserver* external_data_use_observer() const {
-  return external_data_use_observer_.get();
-}
+  chrome::android::ExternalDataUseObserver* external_data_use_observer() const {
+    return external_data_use_observer_.get();
+  }
+
+  base::WeakPtr<chrome::android::DataUseTabModel> data_use_tab_model() const {

[sclittle, 2015/11/18 21:42:04]

Why expose this here? Why not just call
external_data_use_observer()->data_use_tab_model()->GetWeakPtr(), and remove the
stored WeakPtr |data_use_tab_model_| below?

[tbansal1, 2015/11/19 00:47:07]

GetWeakPtr() needs to be called on IO thread. profile_impl* is on UI thread. I
call GetWeakPtr() here on IO, save it, and then just pass it along in
profile_impl*.

+    return data_use_tab_model_;
+  }
 #endif  // defined(OS_ANDROID)
 
  private:
@@ -539,6 +544,8 @@ chrome::android::ExternalDataUseObserver* external_data_use_observer() const {
 #if defined(OS_ANDROID)
   scoped_ptr<chrome::android::ExternalDataUseObserver>
       external_data_use_observer_;
+  // WeakPtr to DataUseTabModel to be used on IO thread.
+  base::WeakPtr<chrome::android::DataUseTabModel> data_use_tab_model_;
 #endif  // defined(OS_ANDROID)
 
   const base::TimeTicks creation_time_;