Make RenderStyle return const Length&'s instead of copying Lengths.

The Length copy constructor does a memcpy and a branch and is
showing up on profiles. There's no need to be copying around
Lengths in the vast majority of cases.

Review URL: https://codereview.chromium.org/189243002

git-svn-id: svn://svn.chromium.org/blink/trunk@168696 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Clear style invalidation bits for shadow roots when walking the DOM to process style invalidation.

BUG=349068

Review URL: https://codereview.chromium.org/189593002

git-svn-id: svn://svn.chromium.org/blink/trunk@168697 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add keishi@ to core/OWNERS.

NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/189463004

git-svn-id: svn://svn.chromium.org/blink/trunk@168698 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Suppress fast/css-generated-content/crash-selection-editing-removes-pseudo.html timeouts on oilpan mac dbg builds.

TBR=leviw
BUG=342574

Review URL: https://codereview.chromium.org/189363003

git-svn-id: svn://svn.chromium.org/blink/trunk@168699 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add suppression: JSON-strigify.html test is keeping DEPS bot failing.

TBR=cbiesinger
BUG=14885
BUG=306929

Review URL: https://codereview.chromium.org/189363004

git-svn-id: svn://svn.chromium.org/blink/trunk@168702 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Output Element defaultValue should be based on textContent

Default value based on textContent if flag is in mode default.

R=tkent, keishi1
BUG=345788
TEST=Check default value based on textContent.

Review URL: https://codereview.chromium.org/178253006

git-svn-id: svn://svn.chromium.org/blink/trunk@168703 bbb929c8-8fbe-4397-9dbb-9b2b20218538