Add VERBOSE->INFO logging level mapping to ExtensionInfoGenerator.

Add VERBOSE->INFO logging level mapping to ExtensionInfoGenerator.
Modify unit test to regress crashing bug and verify the fix.

BUG=469935
Committed: https://crrev.com/9fc8806225dbfe2b33ca0af0ad27ded7e55b66f6
Cr-Commit-Position: refs/heads/master@{#322649}

[Kevin M, 2015-03-24 21:12:10]

kmarshall@chromium.org changed reviewers:
+ rdevlin.cronin@chromium.org

[Devlin, 2015-03-25 18:06:07]

lgtm with comment

https://codereview.chromium.org/1036593003/diff/1/chrome/browser/extensions/a...
File chrome/browser/extensions/api/developer_private/extension_info_generator.cc
(right):

https://codereview.chromium.org/1036593003/diff/1/chrome/browser/extensions/a...
chrome/browser/extensions/api/developer_private/extension_info_generator.cc:106:
case logging::LOG_VERBOSE:
Hmm.  Used to be ExtensionErrors would only ever have a logging of INFO,
WARNING, or ERROR.

Since apparently we can now get VERBOSE, let's also go ahead and add FATAL in
here.

[Kevin M, 2015-03-27 21:05:50]

https://codereview.chromium.org/1036593003/diff/1/chrome/browser/extensions/a...
File chrome/browser/extensions/api/developer_private/extension_info_generator.cc
(right):

https://codereview.chromium.org/1036593003/diff/1/chrome/browser/extensions/a...
chrome/browser/extensions/api/developer_private/extension_info_generator.cc:106:
case logging::LOG_VERBOSE:
On 2015/03/25 18:06:07, Devlin wrote:
> Hmm.  Used to be ExtensionErrors would only ever have a logging of INFO,
> WARNING, or ERROR.
> 
> Since apparently we can now get VERBOSE, let's also go ahead and add FATAL in
> here.

Done.

[Kevin M, 2015-03-27 21:05:53]

The CQ bit was checked by kmarshall@chromium.org

[Kevin M, 2015-03-27 21:05:53]

The patchset sent to the CQ was uploaded after l-g-t-m from
rdevlin.cronin@chromium.org
Link to the patchset: https://codereview.chromium.org/1036593003/#ps20001
(title: "Code review feedback & resync with master")

[commit-bot: I haz the power, 2015-03-27 21:06:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1036593003/20001

[commit-bot: I haz the power, 2015-03-27 21:49:42]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-27 21:50:31]

Patchset 2 (id:??) landed as
https://crrev.com/9fc8806225dbfe2b33ca0af0ad27ded7e55b66f6
Cr-Commit-Position: refs/heads/master@{#322649}