cc: Add CopyAsBitmapRequest class to hold the readback callback.

cc: Add CopyAsBitmapRequest class to hold the readback callback.

Currently when you request an async copy of a layer as a bitmap, we
pass around the raw base::Callback. In order to add functionality to
the copy/readback mechanism, we need to pass along other parameters
such as a size to scale the copy to. Instead of passing along an
ever-growing list of parameters, wrap the base::Callback in a class
called CopyAsBitmapRequest. Then new parameters can be added to this
class.

No change in behaviour here, covered by existing tests.

R=piman
BUG=242571
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=201990

[piman, 2013-05-21 20:39:00]

lgtm

[commit-bot: I haz the power, 2013-05-21 20:41:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/danakj@chromium.org/15435003/2001

[piman, 2013-05-23 21:02:35]

lgtm

[commit-bot: I haz the power, 2013-05-23 21:23:26]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/danakj@chromium.org/15435003/23001

[commit-bot: I haz the power, 2013-05-24 06:45:37]

Change committed as 201990