Add support for size checking selection based scans.

Add support for size checking selection based scans.

* Check size of scans.
* Create and cache selection scans (needed to check their size)....but only cache until the next selection change.
* Improve test coverage, covering both "while importing" and "insufficient size" cases.
* Improve tests to check for labels too (uncovering one bug in the test).
* Fix bug where we were no-longer updating import state/widget on selection changes.

BUG=420680
TEST=browser_test: FileManagerJsTest.*

Need a review from either mtomasz@ or hirono@, not both. First one to review, kindly remove the other.

Committed: https://crrev.com/5d287529f3f821240e35ab8078fdb698d5c84ba5
Cr-Commit-Position: refs/heads/master@{#314159}

[Steve McKay, 2015-01-30 21:23:10]

smckay@chromium.org changed reviewers:
+ kenobi@chromium.org, mtomasz@chromium.org

[Steve McKay, 2015-01-30 21:24:02]

CC +hirono since I promised him this CL.
Assigned mtomasz as reviewer since he said he'll be around.

[Steve McKay, 2015-01-30 21:30:03]

Reinstate all test cases.

[Ben Kwa, 2015-01-30 21:45:58]

https://codereview.chromium.org/886093003/diff/20001/ui/file_manager/file_man...
File ui/file_manager/file_manager/foreground/js/import_controller.js (right):

https://codereview.chromium.org/886093003/diff/20001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:625:
this.scanner_.scan(entries);
The last selection scan result is never actually getting cached.

[Steve McKay, 2015-01-30 22:42:31]

Update DefaultScanResult to use importerResolver instead of hand rolled
support...was investigating heisenbug

[Steve McKay, 2015-01-30 22:43:00]

PTAL.

https://codereview.chromium.org/886093003/diff/20001/ui/file_manager/file_man...
File ui/file_manager/file_manager/foreground/js/import_controller.js (right):

https://codereview.chromium.org/886093003/diff/20001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:625:
this.scanner_.scan(entries);
On 2015/01/30 21:45:58, Ben Kwa wrote:
> The last selection scan result is never actually getting cached.

Done.

[Ben Kwa, 2015-01-30 23:13:09]

lgtm

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
File ui/file_manager/file_manager/background/js/media_scanner.js (right):

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/background/js/media_scanner.js:291: /** @return
{function()} */
I think this is the reason your refactoring addressed the type issue: the type
of the resolve function being passed to the .then call above has gone back to
{function()}, whereas in your intermediate code it was... something else.

[Steve McKay, 2015-01-30 23:18:02]

Thanks.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
File ui/file_manager/file_manager/background/js/media_scanner.js (right):

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/background/js/media_scanner.js:291: /** @return
{function()} */
On 2015/01/30 23:13:09, Ben Kwa wrote:
> I think this is the reason your refactoring addressed the type issue: the type
> of the resolve function being passed to the .then call above has gone back to
> {function()}, whereas in your intermediate code it was... something else.

But the issue was only when I had individually selected files...not for all
scans. Seems like if the issue was related to the original code...then it would
have affected *all* scans.

[Steve McKay, 2015-02-01 05:17:44]

Hirono-san. Added you as I'm not sure Tomasz will get to this by Monday.

[hirono, 2015-02-02 01:07:00]

hirono@chromium.org changed reviewers:
+ hirono@chromium.org

[hirono, 2015-02-02 01:07:01]

lgtm with commnets. Thanks!

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
File ui/file_manager/file_manager/foreground/js/import_controller.js (right):

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:132:
this.scanManager_.reset();
It's better to reset cache when the import is finished in another window.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:319:
this.scanManager_.reset();
nit: We can check volume-unmounted event in the background page, and invalidate
the scan of unmounted volume to notify the foreground page of it.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:589:
this.cachedScans_ = {};
Do we need to have multiple scan caches? If we had multiple caches, all of them
would be cleared when one scan was invalidated or import was finished.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:611:
this.cachedScans_ = {};
Please check whether the scans are invalidated or not.

[Steve McKay, 2015-02-02 15:52:37]

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
File ui/file_manager/file_manager/foreground/js/import_controller.js (right):

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:132:
this.scanManager_.reset();
On 2015/02/02 01:07:01, hirono wrote:
> It's better to reset cache when the import is finished in another window.

Ahh, yeah. Multiple-windows. Good thinking. We probably need to push the scan
cache and as well as active import details into the background so it can be
shared.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:319:
this.scanManager_.reset();
On 2015/02/02 01:07:01, hirono wrote:
> nit: We can check volume-unmounted event in the background page, and
invalidate
> the scan of unmounted volume to notify the foreground page of it.

Yep. Basically the same TODO (moving scan cache and active import into
background)...already added to backlog.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:589:
this.cachedScans_ = {};
On 2015/02/02 01:07:01, hirono wrote:
> Do we need to have multiple scan caches? If we had multiple caches, all of
them
> would be cleared when one scan was invalidated or import was finished.

TODO will address this...and make the need for multiple cached scans more
apparent.

https://codereview.chromium.org/886093003/diff/40001/ui/file_manager/file_man...
ui/file_manager/file_manager/foreground/js/import_controller.js:611:
this.cachedScans_ = {};
On 2015/02/02 01:07:01, hirono wrote:
> Please check whether the scans are invalidated or not.

That would be unnecessary coupling with the calling code. The responsibility of
this class is simply to clear directory scans when told to do so.

Though once we move this to the background, that might change.

[Steve McKay, 2015-02-02 15:52:41]

The CQ bit was checked by smckay@chromium.org

[commit-bot: I haz the power, 2015-02-02 15:53:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/886093003/40001

[commit-bot: I haz the power, 2015-02-02 16:59:04]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-02 17:00:07]

Patchset 3 (id:??) landed as
https://crrev.com/5d287529f3f821240e35ab8078fdb698d5c84ba5
Cr-Commit-Position: refs/heads/master@{#314159}