Add a browser test for access control for file: scheme

chrome/browser/net/chrome_network_delegate.h

Index: chrome/browser/net/chrome_network_delegate.h
diff --git a/chrome/browser/net/chrome_network_delegate.h b/chrome/browser/net/chrome_network_delegate.h
index 8937c09b504573546980dbd2ef6c2fb85c7e51f2..597c65cdc3a74757e41e65450bf50b06635220d8 100644
--- a/chrome/browser/net/chrome_network_delegate.h
+++ b/chrome/browser/net/chrome_network_delegate.h
@@ -134,6 +134,11 @@ class ChromeNetworkDelegate : public net::NetworkDelegateImpl {
   static bool IsAccessAllowed(const base::FilePath& path,
                               const base::FilePath& profile_path);
 
+  // Enables access to all files for testing purposes. This function is used
+  // to bypass the access control for file: scheme. Calling this function
+  // with false brings back the original (production) behaviors.
+  static void EnableAccessToAllFilesForTesting(bool enabled);
+
  private:
   // NetworkDelegate implementation.
   int OnBeforeURLRequest(net::URLRequest* request,