Use base::string16 for user-visible texts in ContentSuggestion

Use base::string16 for user-visible texts in ContentSuggestion

Because some providers (like the bookmarks provider) have their strings
available in UTF-16 encoding, we should use these throughout. The
NTPSnippetsService needs to continue using std::string because the JSON
format does not support UTF-16.

BUG=633141
Committed: https://crrev.com/fec302508285401ac5a98f8d9391b22e833ad52f
Cr-Commit-Position: refs/heads/master@{#408971}

[Philipp Keck, 2016-08-01 14:24:24]

pke@google.com changed reviewers:
+ treib@chromium.org

[Marc Treib, 2016-08-01 14:30:42]

lgtm

[Philipp Keck, 2016-08-01 14:58:18]

The CQ bit was checked by pke@google.com

[commit-bot: I haz the power, 2016-08-01 14:58:33]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-01 15:54:48]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-01 15:58:04]

Description was changed from

==========
Use base::string16 for user-visible texts in ContentSuggestion

Because some providers (like the bookmarks provider) have their strings
available in UTF-16 encoding, we should use these throughout. The
NTPSnippetsService needs to continue using std::string because the JSON
format does not support UTF-16.

BUG=633141
==========

to

==========
Use base::string16 for user-visible texts in ContentSuggestion

Because some providers (like the bookmarks provider) have their strings
available in UTF-16 encoding, we should use these throughout. The
NTPSnippetsService needs to continue using std::string because the JSON
format does not support UTF-16.

BUG=633141

Committed: https://crrev.com/fec302508285401ac5a98f8d9391b22e833ad52f
Cr-Commit-Position: refs/heads/master@{#408971}
==========

[commit-bot: I haz the power, 2016-08-01 15:58:05]

Patchset 1 (id:??) landed as
https://crrev.com/fec302508285401ac5a98f8d9391b22e833ad52f
Cr-Commit-Position: refs/heads/master@{#408971}