Keep the 'fetching files' message until the Drive root is ready to be read.

Keep the 'fetching files' message until the Drive root is ready to be read.

For introducing the 'fast-fetch' feature, getDirectory(root)
is changed not to trigger feed loading anymore. To wait for
Drive really ready for operations, we need to wait for directoryReader.readEntries() to finish.

BUG=197246
TEST=Open Files.app > "Google Drive", ctrl-click gear menu and clean local cache. 
Verify spinner with some text "fetching files" is shown, not just a spinner animation.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=189599

[kinaba, 2013-03-21 04:57:42]

ptal.
+mtomasz: as a file-manager OWNER.
+satorux: as a fast-fetch guy.

Note: if fast-fetch ideally works we may not need to care about such
an issue, but for now, without this patch, we cannot fallback
well to normal feed fetching (because it doesn't show the progress text).
Note2: I believe this CL does not sacrifice the goal of fast-fetch.
After all, Files.app cannot do anything until the root directory is ready to
read.

[satorux1, 2013-03-21 05:00:53]

LGTM. Interesting. I wasn't hit by this issue while I was working on fast-fetch.
Why is that?

[kinaba, 2013-03-21 05:10:38]

On 2013/03/21 05:00:53, satorux1 wrote:
> LGTM. Interesting. I wasn't hit by this issue while I was working on
fast-fetch.
> Why is that?

If fast-fetch is really fast :), the message doesn't matter because it is
instant.
Even if it is slow, a spinner image is shown at least, so it doesn't look so
odd.
Have you been seeing the progress text, not just spinner? If you have that's
strange...

[mtomasz, 2013-03-21 05:18:41]

On 2013/03/21 05:10:38, kinaba wrote:
> On 2013/03/21 05:00:53, satorux1 wrote:
> > LGTM. Interesting. I wasn't hit by this issue while I was working on
> fast-fetch.
> > Why is that?
> 
> If fast-fetch is really fast :), the message doesn't matter because it is
> instant.
> Even if it is slow, a spinner image is shown at least, so it doesn't look so
> odd.
> Have you been seeing the progress text, not just spinner? If you have that's
> strange...

I'm not familiar with fast-fetch, but the change in js itself looks good to me.
lgtm.

[commit-bot: I haz the power, 2013-03-21 05:24:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/12978002/1

[commit-bot: I haz the power, 2013-03-21 09:55:57]

Retried try job too often on win7_aura for step(s) interactive_ui_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...

[commit-bot: I haz the power, 2013-03-21 10:46:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/12978002/1

[commit-bot: I haz the power, 2013-03-21 14:00:57]

Retried try job too often on win7_aura for step(s) interactive_ui_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...

[kinaba, 2013-03-21 14:52:30]

Committed patchset #1 manually as r189599 (presubmit successful).