drive: Move RefreshDirectory from ResourceMetadata to ChangeListLoader

drive: Move RefreshDirectory from ResourceMetadata to ChangeListProcessor

RefreshDirectory is a utility function whose only user is ChangeListLoader.

Move RefreshDirectory to ChangeListProcessor.
Use AddEntry instead of RefreshDirectory for grand root.
Discard old complicated tests and write new ones. Empty map case is omitted because it results in almost no-op.

BUG=193525
TEST=unit_tests
R=kinaba@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=218935

[kinaba, 2013-08-22 02:00:21]

On 2013/08/21 11:36:41, hashimoto wrote:

It sounds very good to move RefreshDirectory out of ResourceMetadata,
but can't you move it to ChangeListProcessor rather than the Loader?
I'd rather like to have a separation between them, i.e., CLLoader does
loading (check changestamp, necessity of fast-fetch, and runs API call)
and Processor does feed application (modify ResourceMetadata, and correct
changed paths).

There may be a difficulty, but I'm wondering if we can replace most of
the RefreshDirectory task is covered by just calling
ChangeListProcessor::ApplyEntryMap (after some pre-filtering).

[hashimoto, 2013-08-22 03:24:37]

Sounds good.
Moved the stuffs to the processor.
PTAL

[kinaba, 2013-08-22 04:45:19]

lgtm. nice refactoring

[hashimoto, 2013-08-22 07:45:27]

Committed patchset #4 manually as r218935 (presubmit successful).