Remove dependency from infobars component to the embedder

Remove dependency from infobars component to the embedder

The infobars::InfoBar::kSeparatorLineHeight, ... constants were declared
in the infobars component but only defined in the embedder. Due to that,
the component was not self contained and every client had to contains
those symbols and ensure they were only defined once (or encounter linker
errors).

This instead change the InfoBar and InfoBarContainer implementations to
access the constants through the InfoBarManager. The constants are also
made available through a global to the whole embedder since the value
were used in multiple places.

The constants value depends on the UI system used (cocoa, android, views)
and thus are defined in infobar_service_${ui_system}.cc.

BUG=382924

[sdefresne, 2014-12-03 15:47:01]

Patchset #1 (id:1) has been deleted

[sdefresne, 2014-12-03 15:47:10]

Patchset #1 (id:20001) has been deleted

[sdefresne, 2014-12-03 15:47:16]

Patchset #1 (id:40001) has been deleted

[sdefresne, 2014-12-03 15:48:51]

sdefresne@chromium.org changed reviewers:
+ pkasting@chromium.org, sky@chromium.org

[sdefresne, 2014-12-03 16:16:24]

The other implementation.