Fix for WebView accessible resources.

extensions/browser/renderer_startup_helper.cc

Index: extensions/browser/renderer_startup_helper.cc
diff --git a/extensions/browser/renderer_startup_helper.cc b/extensions/browser/renderer_startup_helper.cc
index 99c7b91de1cd641dc683a84ba674631b1b494dd2..02fea628c959857be17a082b5853b2fcec5aa0fd 100644
--- a/extensions/browser/renderer_startup_helper.cc
+++ b/extensions/browser/renderer_startup_helper.cc
@@ -12,6 +12,7 @@
 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extensions_browser_client.h"
+#include "extensions/browser/guest_view/web_view/web_view_guest.h"
 #include "extensions/common/extension_messages.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/extensions_client.h"
@@ -72,6 +73,8 @@ void RendererStartupHelper::Observe(
           ExtensionMsg_Loaded_Params(ext.get(), include_tab_permissions));
     }
   }
+  process->Send(new ExtensionMsg_SetWebViewPartitionID(

[not at google - send to devlin, 2015/08/31 18:31:44]

You should only need to send it if it's actually a webview host.

and in fact, in light of the IO thread issues, could you pull this into webview
code somewhere?

[paulmeyer, 2015/08/31 21:40:08]

You're right that I should put a guard on here for whether the renderer is
actually a guest, but there should be no thread issues for leaving it here.

+      WebViewGuest::GetPartitionID(process)));
   process->Send(new ExtensionMsg_Loaded(loaded_extensions));
 }