Move chrome/browser/chromeos/drive/file_system.cc (+deps) into components/drive.

Move chrome/browser/chromeos/drive/file_system.cc (+deps) into components/drive.

Previous CL (crrev.com/1318543003) has moved the
chrome/browser/chromeos/drive/file_system/ directory (and its
dependencies) into components/drive.  This CL moves
chrome/browser/chromeos/drive/file_system.cc file (and its dependencies)
into components/drive.

Files moved from chrome/browser/chromeos/drive into components/drive:
- directory_loader*
- dummy_file_system*
- fake_file_system*
- file_system*
- file_system_observer.h
- remove_stale_cache_files*
- search_metadata*
- sync/*
- sync_client*

Test steps:
1. Verify that things still build via GYP.
   $ GYP_DEFINES="use_goma=1 chromeos=1 component=shared_library" gclient sync
   $ ninja -C out/Debug -j 150 chrome unit_tests \
         interactive_ui_tests browser_tests drive

2. Verify that things still build via GN.
  $ gn gen out/Default --args='target_os="chromeos" use_goma=true is_component_build=true'
  $ ninja -C out/Default -j 150 chrome unit_tests \
        interactive_ui_tests browser_tests components/drive

TEST=Please see "Test steps" above.
BUG=257943, 498951
Committed: https://crrev.com/2e964692340581cc6349a334d0f8ebbe601944df
Cr-Commit-Position: refs/heads/master@{#346429}

[Łukasz Anforowicz, 2015-08-28 22:59:53]

[email protected] changed reviewers:
+ [email protected]

[Łukasz Anforowicz, 2015-08-28 22:59:54]

Tomasz, could you please take a look?

[mtomasz, 2015-08-31 06:10:34]

lgtm, awesome!

[Łukasz Anforowicz, 2015-08-31 17:33:16]

The CQ bit was checked by [email protected]

[Łukasz Anforowicz, 2015-08-31 17:33:16]

The patchset sent to the CQ was uploaded after l-g-t-m from [email protected]
Link to the patchset: https://codereview.chromium.org/1314803004/#ps40001
(title: "Rebasing...")

[commit-bot: I haz the power, 2015-08-31 17:33:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1314803004/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1314803004/40001

[commit-bot: I haz the power, 2015-08-31 18:57:30]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-08-31 18:58:06]

Patchset 3 (id:??) landed as
https://crrev.com/2e964692340581cc6349a334d0f8ebbe601944df
Cr-Commit-Position: refs/heads/master@{#346429}