Spec compliant url.search/url.hash setters over empty values.

Setting the URLUtils properties 'search' and 'hash' to empty strings
should result in null query and hash URL components, respectively.

R=arv
BUG=410395

Review URL: https://codereview.chromium.org/537103002

git-svn-id: svn://svn.chromium.org/blink/trunk@181410 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert "Revert "Avoid calling notifyResizeForViewportUnits when viewport wasn't resized.""

This reverts commit f07fdba558448203b3cfcd49cc153be1f0a6713b.

The original CL, https://codereview.chromium.org/533893005 was not a problem

BUG=410268
TBR=tkent, stevet, yoav@yoav.ws, bokan

Review URL: https://codereview.chromium.org/542853002

git-svn-id: svn://svn.chromium.org/blink/trunk@181411 bbb929c8-8fbe-4397-9dbb-9b2b20218538