Inline ScheduleAndForget implementation in HistoryService

Inline ScheduleAndForget implementation in HistoryService

ScheduleAndForget is a thin wrapper around ScheduleTask that hides
a base::Bind() call and passing the HistoryBackend pointer as the
first parameter.

As they are templated function, they prevent splitting HistoryService
into a pure virtual interface and a implementation interface that
would improve the componentization velocity.

BUG=370850
R=droger@chromium.org

Committed: https://crrev.com/f2cd18db42d5ce1404deba163ffdec0fb00f0fad
Cr-Commit-Position: refs/heads/master@{#314006}

[droger, 2015-01-30 16:40:37]

LGTM, but I am not familiar enough with the code to know if the CHECK change is
safe.

https://codereview.chromium.org/865443005/diff/1/chrome/browser/history/histo...
File chrome/browser/history/history_service.cc (right):

https://codereview.chromium.org/865443005/diff/1/chrome/browser/history/histo...
chrome/browser/history/history_service.cc:1027: DCHECK(thread_) << "History
service being called after cleanup";
Not sure if this CHECK should be changed in DCHECK.

[sdefresne, 2015-01-30 20:46:06]

The CQ bit was checked by sdefresne@chromium.org

[commit-bot: I haz the power, 2015-01-30 20:46:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/865443005/20001

[sdefresne, 2015-01-30 21:17:01]

https://codereview.chromium.org/865443005/diff/1/chrome/browser/history/histo...
File chrome/browser/history/history_service.cc (right):

https://codereview.chromium.org/865443005/diff/1/chrome/browser/history/histo...
chrome/browser/history/history_service.cc:1027: DCHECK(thread_) << "History
service being called after cleanup";
On 2015/01/30 at 16:40:37, droger wrote:
> Not sure if this CHECK should be changed in DCHECK.

Changed back to CHECK, thank you.

[commit-bot: I haz the power, 2015-01-30 22:14:34]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-30 22:15:40]

Patchset 2 (id:??) landed as
https://crrev.com/f2cd18db42d5ce1404deba163ffdec0fb00f0fad
Cr-Commit-Position: refs/heads/master@{#314006}