Import the tests for :valid/:invalid on form/fieldset from blink
https://bugs.webkit.org/show_bug.cgi?id=139899

Reviewed by Darin Adler.

blink's tests are incredibly basic but it is better to include them
for completeness.

* fast/forms/fieldset-pseudo-valid-style-expected.txt: Added.
* fast/forms/fieldset-pseudo-valid-style.html: Added.
* fast/forms/form-pseudo-valid-style-expected.txt: Added.
* fast/forms/form-pseudo-valid-style.html: Added.
Both tests are from Bartek Nowierski.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177728 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Simplify saturated integer add/sub
https://bugs.webkit.org/show_bug.cgi?id=139854

Reviewed by Darin Adler.

* wtf/Compiler.h:
Make a wrapper for __has_builtin for compilers that do not support it.

* wtf/SaturatedArithmetic.h:
(saturatedAddition):
(saturatedSubtraction):
Use the builtins when possible instead of reinventing the wheel.
On ARMv7, use the saturated math instructions.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177729 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Small cleanup of RenderBlock::paint()
https://bugs.webkit.org/show_bug.cgi?id=139849

Patch by Benjamin Poulain <bpoulain@apple.com> on 2014-12-24
Reviewed by Daniel Bates.

Remove a couple of instructions by putting variable in the right scope.

* rendering/RenderBlock.cpp:
(WebCore::RenderBlock::paint):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@177730 268f45cc-cd09-0410-ab3c-d52691b4dbfc