[CSS Grid Layout] Refactor testing code
https://bugs.webkit.org/show_bug.cgi?id=119552

Reviewed by Darin Adler.

Based on Blink r148922 & r149060 by <jchaffraix@chromium.org>

The old testing code was a huge copy&paste of big testing code
blocks. Refactor it in some new utility functions so that we could
reduce the size of the layout test file and ease the maintenance.

* fast/css-grid-layout/grid-item-column-row-get-set-expected.txt:
* fast/css-grid-layout/grid-item-column-row-get-set.html:
* fast/css-grid-layout/grid-item-end-after-get-set-expected.txt:
* fast/css-grid-layout/grid-item-end-after-get-set.html:
* fast/css-grid-layout/grid-item-start-before-get-set-expected.txt:
* fast/css-grid-layout/grid-item-start-before-get-set.html:
* fast/css-grid-layout/resources/grid-item-column-row-parsing-utils.js: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154438 268f45cc-cd09-0410-ab3c-d52691b4dbfc
ASSERTION FAILED: extractedStyle in WebCore::ApplyStyleCommand::removeInlineStyleFromElement
https://bugs.webkit.org/show_bug.cgi?id=119672

Reviewed by Darin Adler.

Source/WebCore:

The last extractedStyle parameter of removeInlineStyleFromElement() is not mandatory and it's set
to default 0. This way we have to check its existence before the usage.

Test: editing/execCommand/extracted_style_assert.html

* editing/ApplyStyleCommand.cpp:
(WebCore::ApplyStyleCommand::removeInlineStyleFromElement):

LayoutTests:

Test with NULL extractedStyle.

* editing/execCommand/extracted_style_assert-expected.txt: Added.
* editing/execCommand/extracted_style_assert.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154439 268f45cc-cd09-0410-ab3c-d52691b4dbfc