Avoid blocking the PNaCl translator processes when chrome NaCl GDB flag is on.

chrome/browser/nacl_host/nacl_browser_delegate_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/nacl_host/nacl_browser_delegate_impl.h"
 
 #include "base/path_service.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 145 matching lines @@
     inverse_debug_patterns_ = true;
     debug_patterns.erase(0, 1);
   }
   if (debug_patterns.empty()) {
     return;
   }
   std::vector<std::string> patterns;
   base::SplitString(debug_patterns, ',', &patterns);
   for (std::vector<std::string>::iterator iter = patterns.begin();
        iter != patterns.end(); ++iter) {
-    URLPattern pattern;
+    // Allow chrome:// schema, which is used to filter out the internal
+    // PNaCl translator. Also allow chrome-extension:// schema (which
+    // can have NaCl modules). The default is to disallow these schema
+    // since they can be dangerous in the context of chrome extension
+    // permissions, but they are okay here, for NaCl GDB avoidance.
+    URLPattern pattern(URLPattern::SCHEME_ALL);
     if (pattern.Parse(*iter) == URLPattern::PARSE_SUCCESS) {
       // If URL pattern has scheme equal to *, Parse method resets valid
       // schemes mask to http and https only, so we need to reset it after
-      // Parse to include chrome-extension scheme that can be used by NaCl
-      // manifest files.
+      // Parse to re-include chrome-extension and chrome schema.
       pattern.SetValidSchemes(URLPattern::SCHEME_ALL);
       debug_patterns_.push_back(pattern);
     }
   }
 }
 
 bool NaClBrowserDelegateImpl::URLMatchesDebugPatterns(
     const GURL& manifest_url) {
   // Empty patterns are forbidden so we ignore them.
   if (debug_patterns_.empty()) {
@@ skipping 72 matching lines @@
     return false;
 
   *file_path = resource_file_path;
   return true;
 }
 
 content::BrowserPpapiHost::OnKeepaliveCallback
 NaClBrowserDelegateImpl::GetOnKeepaliveCallback() {
   return base::Bind(&OnKeepalive);
 }