drive: Stop triggering fast fetch when showing filesystem contents in chrome://drive-internals

BUG=341346
TEST=Open chrome://drive-internals, click "Show" button in "File System Contents" section, see no operation begins in "In-flight Operations" section"

Review URL: https://codereview.chromium.org/156523002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249389 0039d316-1c4b-4281-b951-d872f2087c98
4 files changed