drive: Recover cache entries from trashed DB to filter out non-dirty cache files

drive: Recover cache entries from trashed DB to filter out non-dirty cache files

After non-dirty cache files being filtered out during cache file recovery, the destination directory should contain users' necessary files only.

Move the preserved DB to 'trashed' path, instead of deleting it.
Add ResourceMetadataStorage::RecoverCacheEntriesFromTrashedResourceMap to collect cache entries from the trashed DB.
Pass the collected cache entries to FileCache::RecoverFilesFromCacheDirectory.

BUG=277333
TEST=unit_tests
R=kinaba@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=232289

[kinaba, 2013-10-31 09:22:15]

lgtm

[commit-bot: I haz the power, 2013-10-31 11:20:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hashimoto@chromium.org/54223003/120001

[commit-bot: I haz the power, 2013-10-31 16:39:41]

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

[commit-bot: I haz the power, 2013-11-01 02:52:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hashimoto@chromium.org/54223003/120001

[hashimoto, 2013-11-01 05:13:15]

Committed patchset #3 manually as r232289 (presubmit successful).