Call convertToLength in CSSToStyleMap instead of having it inlined

Trivial cleanup; reduce copy-paste in CSSToStyleMap. Note that the
case where the primitive value isn't an appropriate type shouldn't
occur since we generally assume the parser only allows valid types
through so we change it to an assertion here.

BUG=322365

Review URL: https://codereview.chromium.org/98193002

git-svn-id: svn://svn.chromium.org/blink/trunk@162958 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations CSS: Allow positive start-delay animations on the compositor.

(Depends on a fix to the Chromium compositor to properly support negative time offsets https://codereview.chromium.org/95603003 .)

As we now can directly forward the startDelay into timeOffset we no longer adjust the iterationCount.

BUG=324670
DEPENDS=95603003

Review URL: https://codereview.chromium.org/96193002

git-svn-id: svn://svn.chromium.org/blink/trunk@162959 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add test for innerHTML with a wide DOM

We already have a test for testing a "large" DOM
but it only has a single root node, which avoided
some hot paths.

This test is based off of http://jsperf.com/parse-html-type
which was written by a member of the Google+ team who noticed
a regression in our innerHTML performance as of late.

This is a tiny microbenchmark, which happens to catch some
of this regression, but probably isn't one we should
spend a lot of time optimizing (we're already very very fast).

On my machine this clocks at about 6,000 operations per second.

BUG=318251

Review URL: https://codereview.chromium.org/70953002

git-svn-id: svn://svn.chromium.org/blink/trunk@162960 bbb929c8-8fbe-4397-9dbb-9b2b20218538