Clean up forward declarations in core/rendering and core/painting

Clean up forward declarations in core/rendering and core/painting

These forward references are not needed anymore. After
this patch, core/rendering and core/painting has no unneeded
forward references any more.

This patch also move some forward declarations into correct
header files.

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=185019

[zhaoze.zhou, 2014-11-07 20:25:03]

zhaoze.zhou@partner.samsung.com changed reviewers:
+ rob.buis@samsung.com

[zhaoze.zhou, 2014-11-07 21:30:10]

zhaoze.zhou@partner.samsung.com changed reviewers:
+ schenney@google.com

[zhaoze.zhou, 2014-11-07 21:37:23]

On 2014/11/07 21:30:10, zhaoze.zhou wrote:
> mailto:zhaoze.zhou@partner.samsung.com changed reviewers:
> + mailto:schenney@google.com

PTAL. thanks.

[kouhei (in TOK), 2014-11-09 23:42:40]

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

[kouhei (in TOK), 2014-11-09 23:42:41]

lgtm

[zhaoze.zhou, 2014-11-10 03:05:04]

The CQ bit was checked by zhaoze.zhou@partner.samsung.com

[commit-bot: I haz the power, 2014-11-10 03:05:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/713553002/20001

[commit-bot: I haz the power, 2014-11-10 03:08:06]

Committed patchset #2 (id:20001) as 185019