Move all the page actions from repaint measurements to repaint pages.

Move all the page actions from repaint measurements to repaint pages.

This is due to 2 reasons:
+ Page specific logic should belong to page, not page test.
+ Simplify the repaint measurement control code, which make
it easier to port repaint to TimelineBasedMeasurement.

Trybot link for repaint.gpu_rasterization.key_mobile_sites_repaint:
https://codereview.chromium.org/1098543002

BUG=444703, 455391
Committed: https://crrev.com/fbd947210ecfb42637eca91ceef059f40eea9c0d
Cr-Commit-Position: refs/heads/master@{#325558}

[nednguyen, 2015-04-16 21:04:42]

Patchset #1 (id:1) has been deleted

[nednguyen, 2015-04-16 21:05:21]

Patchset #1 (id:20001) has been deleted

[nednguyen, 2015-04-16 21:07:36]

nednguyen@google.com changed reviewers:
+ aiolos@chromium.org, vmiura@chromium.org

[vmiura, 2015-04-16 21:52:39]

LGTM

[nednguyen, 2015-04-16 22:39:54]

The CQ bit was checked by nednguyen@google.com

[commit-bot: I haz the power, 2015-04-16 22:42:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1089223003/40001

[commit-bot: I haz the power, 2015-04-16 23:59:03]

Committed patchset #1 (id:40001)

[commit-bot: I haz the power, 2015-04-17 00:01:10]

Patchset 1 (id:??) landed as
https://crrev.com/fbd947210ecfb42637eca91ceef059f40eea9c0d
Cr-Commit-Position: refs/heads/master@{#325558}