Extension-created windows should share the creator's BrowingInstance.

chrome/browser/extensions/api/tabs/tabs_api.cc

Index: chrome/browser/extensions/api/tabs/tabs_api.cc
diff --git a/chrome/browser/extensions/api/tabs/tabs_api.cc b/chrome/browser/extensions/api/tabs/tabs_api.cc
index b88feedd5fd827d6a08ebd4f8173f0752ef922fc..6e029e269675a7c720448543bbda587397b5cb75 100644
--- a/chrome/browser/extensions/api/tabs/tabs_api.cc
+++ b/chrome/browser/extensions/api/tabs/tabs_api.cc
@@ -42,6 +42,7 @@
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_navigator.h"
+#include "chrome/browser/ui/browser_navigator_params.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/panels/panel_manager.h"
@@ -641,11 +642,16 @@ bool WindowsCreateFunction::RunSync() {
 
   Browser* new_window = new Browser(create_params);
 
-  for (std::vector<GURL>::iterator i = urls.begin(); i != urls.end(); ++i) {
-    WebContents* tab = chrome::AddSelectedTabWithURL(

[Devlin, 2016/04/01 17:20:57]

Do we still need browser_tabstrip.h?

[dcheng, 2016/04/01 17:42:00]

Done.

-        new_window, *i, ui::PAGE_TRANSITION_LINK);
+  for (const GURL& url : urls) {
+    chrome::NavigateParams navigate_params(new_window, url,
+                                           ui::PAGE_TRANSITION_LINK);
+    navigate_params.disposition = NEW_FOREGROUND_TAB;
+    navigate_params.source_site_instance =

[Devlin, 2016/04/01 17:20:57]

"Without plumbing through the source SiteInstance, the created window
ends up cross process and unscriptable by the background page that
created it."

I'm not quite sure I follow - don't we sometimes (often) want that?  If an
extension creates a window that has urls to google.com, facebook.com, and
yourbank.com, why would we want that in the same process and scriptable?

[dcheng, 2016/04/01 17:42:00]

It'd cause a navigation from an extension origin to a web origin, which should
process swap. What's broken is if an extension navigates to its own resource, it
can't script itself even though it should be in a 'related browsing context'.

[Devlin, 2016/04/01 18:56:34]

Ah, got it - can you add that to the CL description?

[dcheng, 2016/04/02 00:54:25]

Done.

+        render_frame_host()->GetSiteInstance();
+    chrome::Navigate(&navigate_params);
     if (create_panel) {
-      TabHelper::FromWebContents(tab)->SetExtensionAppIconById(extension_id);
+      TabHelper::FromWebContents(navigate_params.target_contents)
+          ->SetExtensionAppIconById(extension_id);
     }
   }