Add TabStripModel as a parameter of some functions in TabStripModelObserver

chrome/browser/devtools/global_confirm_info_bar.cc

Index: chrome/browser/devtools/global_confirm_info_bar.cc
diff --git a/chrome/browser/devtools/global_confirm_info_bar.cc b/chrome/browser/devtools/global_confirm_info_bar.cc
index d25d08e904df81587d5684aa37fd39ff9b4816e0..edec564710890e80698142f7c2c9830439d2aace 100644
--- a/chrome/browser/devtools/global_confirm_info_bar.cc
+++ b/chrome/browser/devtools/global_confirm_info_bar.cc
@@ -160,7 +160,11 @@ GlobalConfirmInfoBar::~GlobalConfirmInfoBar() {
   }
 }
 
-void GlobalConfirmInfoBar::TabInsertedAt(content::WebContents* web_contents,
+// Do not use |tab_strip_model| as it may be null from the call in
+// TabChangedAt(). If it is ever needed later, the solution is to add a pointer
+// to the TabStripModel as a parameter of TabStripModelObserver::TabChangedAt().
+void GlobalConfirmInfoBar::TabInsertedAt(TabStripModel* tab_strip_model,

[sky, 2016/09/19 22:52:58]

Good comment, but this is still rather rather error prone. How about adding a
function that both this and TabChangedAt call into that doesn't take the
TabStripModel? Alternatively update TabChangedAt to take the TabStripModel too.

[Patrick Monette, 2016/09/20 17:46:54]

Done. Can you double check that the code in TabChangedAt() was redundant?

+                                         content::WebContents* web_contents,
                                          int index,
                                          bool foreground) {
   InfoBarService* infobar_service =
@@ -189,7 +193,7 @@ void GlobalConfirmInfoBar::TabChangedAt(content::WebContents* web_contents,
       InfoBarService::FromWebContents(web_contents);
   auto it = proxies_.find(infobar_service);
   if (it == proxies_.end())
-    TabInsertedAt(web_contents, index, false);
+    TabInsertedAt(nullptr, web_contents, index, false);
 }
 
 void GlobalConfirmInfoBar::OnInfoBarRemoved(infobars::InfoBar* info_bar,