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content/browser/browsing_instance.h

Index: content/browser/browsing_instance.h
diff --git a/content/browser/browsing_instance.h b/content/browser/browsing_instance.h
index fa1acf4c0657647c63a0e01e99a45a2495816dd4..4beb487b9a01a846785609102490334c10ee95a8 100644
--- a/content/browser/browsing_instance.h
+++ b/content/browser/browsing_instance.h
@@ -72,6 +72,12 @@ class CONTENT_EXPORT BrowsingInstance
   // SiteInstance per site.
   scoped_refptr<SiteInstanceImpl> GetSiteInstanceForURL(const GURL& url);
 
+  // Returns a SiteInstance that should be used for subframes when an oopif is
+  // required, but a dedicated process is not. This SiteInstance will be created
+  // if it doesn't already exist. There is at most one of these per
+  // BrowsingInstance.
+  scoped_refptr<SiteInstanceImpl> GetDefaultSubframeSiteInstance();
+
   // Adds the given SiteInstance to our map, to ensure that we do not create
   // another SiteInstance for the same site.
   void RegisterSiteInstance(SiteInstanceImpl* site_instance);
@@ -118,6 +124,8 @@ class CONTENT_EXPORT BrowsingInstance
   // Number of WebContentses currently using this BrowsingInstance.
   size_t active_contents_count_;
 
+  SiteInstanceImpl* default_subframe_site_instance_ = nullptr;
+
   DISALLOW_COPY_AND_ASSIGN(BrowsingInstance);
 };