Cache user agent string in FrameLoaderClientImpl instead of BlinkPlatformImpl

Cache user agent string in FrameLoaderClientImpl instead of BlinkPlatformImpl

This CL makes FrameLoaderClientImpl cache user agent string instead of
BlinkPlatformImpl to avoid threading issue.

BUG=598479
Committed: https://crrev.com/40696fd9bf6a11db52416ccf98f129e72df47f73
Cr-Commit-Position: refs/heads/master@{#383915}

[hajimehoshi, 2016-03-29 10:04:36]

hajimehoshi@chromium.org changed reviewers:
+ esprehn@chromium.org

[hajimehoshi, 2016-03-29 10:04:36]

PTAL

[kouhei (in TOK), 2016-03-29 10:30:35]

kouhei@chromium.org changed reviewers:
+ kouhei@chromium.org, tzik@chromium.org

[kouhei (in TOK), 2016-03-29 10:30:35]

+tzik

[tzik, 2016-03-29 12:27:06]

lgtm

[esprehn, 2016-03-29 21:33:37]

lgtm

[hajimehoshi, 2016-03-30 04:39:22]

The CQ bit was checked by hajimehoshi@chromium.org

[commit-bot: I haz the power, 2016-03-30 04:40:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1839023002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1839023002/1

[commit-bot: I haz the power, 2016-03-30 05:40:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-30 05:41:50]

Description was changed from

==========
Cache user agent string in FrameLoaderClientImpl instead of BlinkPlatformImpl

This CL makes FrameLoaderClientImpl cache user agent string instead of
BlinkPlatformImpl to avoid threading issue.

BUG=598479
==========

to

==========
Cache user agent string in FrameLoaderClientImpl instead of BlinkPlatformImpl

This CL makes FrameLoaderClientImpl cache user agent string instead of
BlinkPlatformImpl to avoid threading issue.

BUG=598479

Committed: https://crrev.com/40696fd9bf6a11db52416ccf98f129e72df47f73
Cr-Commit-Position: refs/heads/master@{#383915}
==========

[commit-bot: I haz the power, 2016-03-30 05:41:51]

Patchset 1 (id:??) landed as
https://crrev.com/40696fd9bf6a11db52416ccf98f129e72df47f73
Cr-Commit-Position: refs/heads/master@{#383915}