Harden the implementation of '--disable-web-security'

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 1c1102bcf0520a4a60852a75609babb5c55fcaac..d9722468be50091a45e2f7d30d3530ef66b735db 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -423,6 +423,20 @@ void RendererBlinkPlatformImpl::suddenTerminationChanged(bool enabled) {
     thread->Send(new RenderProcessHostMsg_SuddenTerminationChanged(enabled));
 }
 
+bool RendererBlinkPlatformImpl::canGrantUniversalAccess() {
+  if (!GetContentClient()
+           ->renderer()
+           ->ShouldEnforceUniversalAccessRestrictions()) {
+    return true;
+  }
+  bool is_access_grantable = false;
+  if (RenderThread* thread = RenderThread::Get()) {

[esprehn, 2015/12/10 08:06:44]

how is it possible that this is null? I don;t think we can be here and not have
a RenderThread.

+    thread->Send(new RenderProcessHostMsg_GetUniversalAccessDisposition(

[Marshall, 2015/12/09 14:20:22]

Since the result of this sync IPC call is effectively static it might be better
to either (a) cache the result from a single call or (b) pass the
kDisableWebSecurity flag to the renderer process and check it there instead of
using an IPC.

[jochen (gone - plz use gerrit), 2015/12/10 15:39:32]

a compromised renderer can just not ask the browser

+        &is_access_grantable));
+  }
+  return is_access_grantable;
+}
+
 WebStorageNamespace* RendererBlinkPlatformImpl::createLocalStorageNamespace() {
   return new WebStorageNamespaceImpl();
 }