Refactor ExtensionManifestTest to allow usage in src/extensions

Refactor ExtensionManifestTest to allow usage in src/extensions

This refactor will allow some manifest tests running in Chrome's unit_tests
suite to move to the extensions_unittests suite.

* Rename ExtensionManifestTest to extensions::ManifestTest and move it into
  src/extensions.
* Introduce ChromeManifestTest to load manifests from Chrome's test data dir.
* Eliminate some unnecessary use of chrome::VersionInfo::Channel.
* Move SharedModuleManifestTest to extensions_unittests as an example.

FileHandlerManifestTest and ExternallyConnectableManifestTest will be next,
but require more refactoring (e.g. of permissions).

BUG=397165
TEST=unit_tests, extensions_unittests

Committed: https://crrev.com/bd1cc624f6fd9761409ee8a8ac5cfd3a5896c87a
Cr-Commit-Position: refs/heads/master@{#295087}

[James Cook, 2014-09-16 00:51:48]

jamescook@chromium.org changed reviewers:
+ rockot@chromium.org

[James Cook, 2014-09-16 00:51:50]

Ken, PTAL.  The only interesting bits are the changes in manifest_test.cc

(Let me know if you'd like me to do more test suite renames or extensions
namespace cleanup in this CL -- I avoided it to keep the CL smaller.)

https://codereview.chromium.org/572813002/diff/1/extensions/common/manifest_t...
File extensions/common/manifest_test.h (left):

https://codereview.chromium.org/572813002/diff/1/extensions/common/manifest_t...
extensions/common/manifest_test.h:81: char const* manifest_json);
Unused, deleted it and associated dead code.

[Ken Rockot(use gerrit already), 2014-09-16 16:20:20]

nice. LGTM, and renaming in a follow-up CL sgtm.

https://codereview.chromium.org/572813002/diff/1/extensions/common/manifest_t...
File extensions/common/manifest_test.h (left):

https://codereview.chromium.org/572813002/diff/1/extensions/common/manifest_t...
extensions/common/manifest_test.h:81: char const* manifest_json);
On 2014/09/16 00:51:50, James Cook wrote:
> Unused, deleted it and associated dead code.

Woot! Kill ALL the dead code!

[James Cook, 2014-09-16 16:26:08]

The CQ bit was checked by jamescook@chromium.org

[commit-bot: I haz the power, 2014-09-16 16:29:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/572813002/1

[commit-bot: I haz the power, 2014-09-16 17:02:59]

Committed patchset #1 (id:1) as 53e88af5bb89cb7e409ba843b1495b0a33dc286f

[commit-bot: I haz the power, 2014-09-16 17:04:16]

Patchset 1 (id:??) landed as
https://crrev.com/bd1cc624f6fd9761409ee8a8ac5cfd3a5896c87a
Cr-Commit-Position: refs/heads/master@{#295087}

[James Cook, 2014-09-16 23:53:43]

On 2014/09/16 17:04:16, I haz the power (commit-bot) wrote:
> Patchset 1 (id:??) landed as
> https://crrev.com/bd1cc624f6fd9761409ee8a8ac5cfd3a5896c87a
> Cr-Commit-Position: refs/heads/master@{#295087}

Reverted, see https://codereview.chromium.org/574173002/