Propogate the tab foreground, background change events to data use

chrome/browser/data_use_measurement/data_use_web_contents_observer.h

Index: chrome/browser/data_use_measurement/data_use_web_contents_observer.h
diff --git a/chrome/browser/data_use_measurement/data_use_web_contents_observer.h b/chrome/browser/data_use_measurement/data_use_web_contents_observer.h
index ba8d7d240a9c35bc8f9670c88580de327d2c847c..4b57a7e1cd21340fd6229cf8f7f9f63a5c4877b4 100644
--- a/chrome/browser/data_use_measurement/data_use_web_contents_observer.h
+++ b/chrome/browser/data_use_measurement/data_use_web_contents_observer.h
@@ -40,6 +40,13 @@ class DataUseWebContentsObserver
   void ReadyToCommitNavigation(
       content::NavigationHandle* navigation_handle) override;
 
+  // Called every time the WebContents changes visibility.

[RyanSturm, 2016/12/13 22:04:20]

Can you remove this comment and delete the whitespace between the methods from
WebContentsObserver implementation.

[Raj, 2016/12/14 23:00:50]

Done.

+  void WasShown();
+  void WasHidden();
+
+  void RenderFrameHostChanged(content::RenderFrameHost* old_host,
+                              content::RenderFrameHost* new_host);
+
  private:
   friend class content::WebContentsUserData<DataUseWebContentsObserver>;
   DataUseWebContentsObserver(content::WebContents* web_contents,