OOPIF: Prevent process swap when not sharing the StoragePartition.

content/browser/frame_host/render_frame_host_manager.cc

Index: content/browser/frame_host/render_frame_host_manager.cc
diff --git a/content/browser/frame_host/render_frame_host_manager.cc b/content/browser/frame_host/render_frame_host_manager.cc
index 3ec87d36263b55afd0769088dbaf5edcc6980a7e..66dcee66dcc35059bf923b25ab6f54857474fe07 100644
--- a/content/browser/frame_host/render_frame_host_manager.cc
+++ b/content/browser/frame_host/render_frame_host_manager.cc
@@ -40,6 +40,7 @@
 #include "content/common/frame_owner_properties.h"
 #include "content/common/site_isolation_policy.h"
 #include "content/common/view_messages.h"
+#include "content/public/browser/browser_context.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/render_process_host_observer.h"
 #include "content/public/browser/render_widget_host_iterator.h"
@@ -772,6 +773,20 @@ RenderFrameHostImpl* RenderFrameHostManager::GetFrameHostForNavigation(
     no_renderer_swap |= !CanSubframeSwapProcess(
         request.common_params().url, request.source_site_instance(),
         request.dest_site_instance(), was_server_redirect);
+
+    // Even if the url should warrant a process swap, check if the newly
+    // created SiteInstance would use the same StoragePartition as its parent.
+    // If that's not the case, the subframe should not swap processes, as there
+    // is not support for having an OOPIF that does not share the storage

[nasko, 2017/03/06 18:12:07]

nit: StoragePartition.

+    // partition of its parent.
+    BrowserContext* browser_context =
+        frame_tree_node_->navigator()->GetController()->GetBrowserContext();
+    no_renderer_swap |= BrowserContext::GetStoragePartition(
+                            browser_context, dest_site_instance.get()) !=
+                        BrowserContext::GetStoragePartition(
+                            browser_context, frame_tree_node_->parent()
+                                                 ->current_frame_host()
+                                                 ->GetSiteInstance());
   }
 
   if (no_renderer_swap) {