ChildProcessSecurityPolicy: Remove CanReadDirectory (special directory enumeration grant).

Per discussion with kinuko here (https://codereview.chromium.org/24631002/), there is no longer a need for a special directory enumeration permission grant.

This is part of Step 4 of this refactoring plan:
https://docs.google.com/a/google.com/document/d/1QGkGWuwgSuaRqovz4wyb0upqPKDVsgYOFKt44E7gmOE/edit?usp=sharing

BUG=262142, 263150

Review URL: https://codereview.chromium.org/25601002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@227304 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index a3aa086..b2d98cf 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -2452,7 +2452,7 @@
 
   ChildProcessSecurityPolicyImpl* policy =
       ChildProcessSecurityPolicyImpl::GetInstance();
-  if (policy->CanReadDirectory(GetRenderProcessHost()->GetID(), path))
+  if (policy->CanReadFile(GetRenderProcessHost()->GetID(), path))
     delegate_->EnumerateDirectory(this, request_id, path);
 }