Disable painting in a few more places

When GraphicsContext is given a NULL canvas, it should disable painting.
This patch amends a few operations where this check wasn't done. Most
notably, we no longer record display lists when painting is disabled.

BUG=357572

Review URL: https://codereview.chromium.org/216553003

git-svn-id: svn://svn.chromium.org/blink/trunk@170332 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert r170330 "DevTools: Start/Stop overview recording for available mode"
Breaks front-end compilation.

TBR=pan.deng

Review URL: https://codereview.chromium.org/216723003

git-svn-id: svn://svn.chromium.org/blink/trunk@170333 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: only notify enabled presentation modes upon timeline start/end.

R=loislo@chromium.org

Review URL: https://codereview.chromium.org/216833002

git-svn-id: svn://svn.chromium.org/blink/trunk@170334 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[New Multicolumn] balancer confused by content with top margins.

We need to set zero page logical height in LayoutState when column
height is unknown (when the columns haven't yet been
balanced). There's code that assumes that non-zero page height means
that page height is known. Lying about this makes the pagination code
believe that every top margin is adjacent to a column break, which
makes it eat and ignore all top margins.

This should be cleaned up, but it's easier to wait until the old
multicol code has been removed.

BUG=353587

Review URL: https://codereview.chromium.org/209863003

git-svn-id: svn://svn.chromium.org/blink/trunk@170335 bbb929c8-8fbe-4397-9dbb-9b2b20218538