The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ab07704baf9c5efe1d4b0607ed28679bb03836b6

commit ab07704baf9c5efe1d4b0607ed28679bb03836b6
Author: Karan Bhatia <karandeepb@chromium.org>
Date: Tue Aug 22 22:22:53 2017

ChromeExtensionLoader: Prevent redundant loading of unpacked extensions.

Unpacked extensions loaded through the ChromeTestExtensionLoader are loaded
twice. The redundant load is due to the  false default value of
|allow_file_access_|. However, unpacked extensions are by default, loaded with
file access. This mismatch causes the unpacked extensions to be reloaded in
ChromeTestExtensionLoader::CheckPermissions.

Prevent this reload by using Manifest::ShouldAllowFileAccess for cases where
clients don't explicitly set |allow_file_access_|.

BUG= 757695 

Change-Id: Ied4b25ccb89ff1410072186d360634609b8666e5
Reviewed-on: https://chromium-review.googlesource.com/625247
Reviewed-by: Devlin <rdevlin.cronin@chromium.org>
Commit-Queue: Karan Bhatia <karandeepb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496472}
[modify] https://crrev.com/ab07704baf9c5efe1d4b0607ed28679bb03836b6/chrome/browser/extensions/chrome_test_extension_loader.cc
[modify] https://crrev.com/ab07704baf9c5efe1d4b0607ed28679bb03836b6/chrome/browser/extensions/chrome_test_extension_loader.h